Reference Manual
Welcome!......................................................................................................3
DEQ830 Key Features .................................................................... 4
How to Use This Manual................................................................ 5
Instructions de Sécurité Importantes (French) ...................... 9
Symboles utilisés dans ce produit.............................................................9
Veuillez suivre ces précautions lors de l’utilisation de
l’appareil: ......................................................................................................9
Lesen Sie bitte die folgende Sicherheitshinweise
(German) ........................................................................................... 11
Folgen Sie bitte diesen Vorkehrungen, wenn dieses
Produkt verwendet wird: ...........................................................................11
FCC Compliance Statement ......................................................... 13
If you can't wait to get started..................................................................15
Step 3: Store the Program............................................................. 16
Installing in a Rack ........................................................................ 19
Thermal Considerations in Rack Mounting ............................. 19
AC Power Hookup........................................................................... 20
Using the DEQ830 in another country...................................................20
Connecting Inputs and Outputs.................................................. 21
Connecting to the Channel or Main Inserts of a mixing
console..........................................................................................................21
Connecting to the inserts on an instrument amplifier..........................23
Connecting to equipment with XLR inputs and outputs.....................23
Connecting to equipment with ADAT Optical inputs and
outputs..........................................................................................................23
About Audio Cables ........................................................................ 25
Chapter Three: Basics of Equalization...................27
What is equalization? ..................................................................... 27
Description of the Front Panel.................................................... 28
Description of the Basic Modes ................................................... 31
Basic operation: Program mode.................................................. 34
1
Table Of Contents
Basic operation: Save Curve mode ............................................. 41
Basic operation: Retrieve Curve mode ...................................... 41
Basic operation: Utility mode ...................................................... 45
Demonstration mode.................................................................................50
Lock mode...................................................................................................50
Equalization Artifacts.................................................................... 51
Chapter Four: Applications.......................................57
General EQ tips ............................................................................... 57
Filtering effects ............................................................................... 58
Settings chart................................................................................... 59
Chapter Five: Troubleshooting ................................61
Line Conditioners and Protectors .............................................. 61
Care and Maintenance................................................................... 61
Troubleshooting Index ..............................................................................62
Specifications...................................................................65
Audio Performance ....................................................................................65
Mechanical ...................................................................................................65
Warranty/Contact Alesis ............................................67
Alesis Limited Warranty.............................................................................67
Alesis Contact Information.......................................................................68
2
Introduction
Welcome!
Thank you for purchasing the Alesis DEQ830. It is a versatile
product, and whether it becomes a part of your studio or finds its
place in your live setup, we know it will serve you well. Since 1984,
we’ve been designing and building creative tools for the audio
community. We believe in our products, because we've heard the
results that creative people like you achieve with them.
For more effective
service and product
update notices, please
register your DEQ830
online at:
One of the goals of Alesis is to make high-quality music
technology available to everyone. This Reference Manual is an
important part of that, because in it we try to present the
DEQ830’s features in a way that is easy to understand and
remember. But even beyond explaining each feature and
parameter, this manual can be a key that unlocks an application for
the DEQ830 that you may not have considered. So we try to write
our manuals as carefully as we build our products.
The goal of this manual is to get you the information you need as
quickly as possible, with a minimum of hassle. We hope we've
achieved that. If not, please drop us an email and give us your
suggestions on how we could improve future editions of this
manual.
We hope your investment will bring you many years of creative
enjoyment and help you achieve your goals.
Sincerely,
The people of Alesis
3
Introduction
DEQ830 Key Features
1. Offers the best of digital technology and analog-style control: a
graphic display with instant editing of any band or
combination of bands, plus the ability to store programs
2. 100 user-definable programs, each of which holds 8 channels
of EQ settings
3. 100 user-definable curves, each of which holds 30 bands of
EQ settings
4. 48 KHz sampling rate, 24-bit A/D/A, 28-bit internal
processing
5. Eight channels of equalization, independent or linkable
6. 30 EQ bands per channel, spanning 25 Hz-20 KHz in 1/3-
octave increments
7. +/- 12 dB boost/cut with center detente
8. Constant Q technology for finer control of audio
9. LOCK function for “set and forget” situations, which prevents
accidental reprogramming
10. Retrieve Curve mode for auditioning and selecting stored EQ
curves
11. Individual Channel Level adjustment per program
12. Master Level adjustment
13. [LINK] button for quick creation of matched EQ curves
14. Ability to bypass any or all channels using [BYPASS] and
[BYPASS ALL] buttons
15. Configurable editing modes to suit the way you work
16. Ability to copy settings from one channel to another
17. Easy-to-read 7-segment Numerical LED Display
18. More than 350 Band Gain LEDs, making it easy to read EQ
curves from a distance
19. Signal Level, Clip and Bypass LEDs for each channel
20. Balanced input/output (TRS)
21. Compact 1-space rackmount profile
22. Real-time Analyzer (RTA) mode for visual feedback of
incoming and outgoing audio signals, with selectable metering
modes
23. ADAT Optical input/output, auto-sensing of incoming digital
audio
24. Clock selectable between 44.1k and 48k sampling rates
25. MIDI in/out for program changes and sys-ex storage
26. +4 dBu/-10 dBV operating level switch on rear panel
For full operating specifications, see page 65.
4
Introduction
How to Use This Manual
This manual is divided into the following sections describing the
various functions of and applications for the DEQ830. While it's a
good idea to read through the entire manual once carefully, those
having general knowledge about audio equipment should use the
table of contents to look up specific functions.
Helpful tips and advice are
highlighted in a shaded box
like this.
Chapter 1: Quick Start Guide. If you're already familiar with
equalization, this will get you started using the DEQ830 right away.
This section presents the essential elements of hooking up the unit
and using it for the first time.
The names of specific buttons
on the DEQ830 are printed in
a bold font and bracketed:
e.g., the [BYPASS] button.
Chapter 2: Connections. This section gives detailed instructions for
connecting the DEQ830 to a variety of typical audio systems.
Chapter 3: Basics of Equalization. This section describes what an
equalizer does and explains the function of each of the controls.
Chapter 4: Applications. Skip to this section for tips on using the
DEQ830 in a variety of settings. You’ll also find a blank chart
representing the DEQ830’s 30 bands of EQ. You can make copies
of this chart and use them to keep track of some of your
favorite settings.
When something important
appears in the manual, an
exclamation mark (like the
one shown at left) will appear
with some explanatory text.
This symbol indicates that
this information is vital when
operating the DEQ830.
Chapter 5: Troubleshooting. Near the end of the manual you will
find troubleshooting tips and a complete list of the DEQ830’s
specifications.
5
Introduction
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6
Important Safety
Instructions
Important Safety Instructions (English)
Safety symbols used in this product
This symbol alerts the user that there are important
operating and maintenance instructions in the literature
accompanying this unit.
This symbol warns the user of uninsulated voltage within
the unit that can cause dangerous electric shocks.
This symbol warns the user that output connectors contain
voltages that can cause dangerous electrical shock.
Please follow these precautions when using
this product:
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with a damp cloth. Do not spray any liquid cleaner
onto the faceplate, as this may damage the front panel controls
or cause a dangerous condition.
7. Install in accordance with the manufacturer's instructions.
8. Do not install near any heat sources such as radiators, heat
registers, stoves, or other apparatus (including amplifiers) that
produce heat.
9. Do not defeat the safety purpose of the polarized or
grounding-type plug. A polarized plug has two blades with one
wider than the other. A grounding-type plug has two blades
and a third grounding prong. The wide blade or the third
prong are provided for your safety. When the provided plug
does not fit into your outlet, consult an electrician for
replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched,
particularly at plugs, convenience receptacles, and the point
where they exit from the apparatus.
11. Use only attachments or accessories specified by the
manufacturer.
Continued next page
7
Important Safety Instructions
12. Use only with a cart, stand, bracket, or table designed for use
with professional audio or music equipment. In any
installation, make sure that injury or damage will not result
from cables pulling on the apparatus and its mounting. If a
cart is used, use caution when moving the cart/apparatus
combination to avoid injury from tip-over.
13. Unplug this apparatus during lightning storms or when unused
for long periods of time.
14. Refer all servicing to qualified service personnel. Servicing is
required when the apparatus has been damaged in any way,
such as when the power-supply cord or plug is damaged, liquid
has been spilled or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture, does not
operate normally, or has been dropped.
15. This unit produces heat when operated normally. Operate in a
well-ventilated area with at least six inches of clearance from
peripheral equipment.
16. This product, in combination with an amplifier and
headphones or speakers, may be capable of producing sound
levels that could cause permanent hearing loss. Do not operate
for a long period of time at a high volume level or at a level
that is uncomfortable. If you experience any hearing loss or
ringing in the ears, you should consult an audiologist.
17. Do not expose the apparatus to dripping or splashing. Do not
place objects filled with liquids (flower vases, soft drink cans,
coffee cups) on the apparatus.
18. WARNING: To reduce the risk of fire or electric shock, do
not expose this apparatus to rain or moisture.
19. The unit is an audio device, whose power supply may be
subject to surrounding electronic interference. Once installed,
if you find that the unit is malfunctioning, the problem may
be solved by resetting the unit, relocating the unit, or by
installing a line-conditioner.
8
Important Safety Instructions
Instructions de Sécurité Importantes (French)
Symboles utilisés dans ce produit
Ce symbole alèrte l’utilisateur qu’il existe des instructions
de fonctionnement et de maintenance dans la documentation
jointe avec ce produit.
Ce symbole avertit l’utilisateur de la présence d’une
tension non isolée à l’intérieur de l’appareil pouvant engendrer des
chocs électriques.
Ce symbole prévient l'utilisateur de la présence de tensions
sur les raccordements de sorties, représentant un risque
d'électrocution.
Veuillez suivre ces précautions lors de
l’utilisation de l’appareil:
1. Lisez ces instructions.
2. Gardez ces instructions.
3. Tenez compte de tous les avertissements.
4. Suivez toutes les instructions.
5. N’utilisez pas cet allareil à proximité de l’eau.
6. Ne nettoyez qu’avec un chiffon humide. Il est potentiellement
dangereux d'utiliser des pulvérisateurs ou nettoyants liquides
sur cet appareil.
7. Installez selon les recommandations du constructeur.
8. Ne pas installer à proximilé de sources de chaleur comme
radiateurs, cuisinière ou autre appareils (don’t les
amplificateurs) produisant de la chaleur.
9. Ne pas enlever la prise de terre du cordon secteur. Une prise
murale avec terre deux broches et une troisièrme reliée à la
terre. Cette dernière est présente pour votre sécurité. Si le
cordon secteur ne rentre pas dans la prise de courant,
demandez à un électricien qualifié de remplacer la prise.
10. Evitez de marcher sur le cordon secteur ou de le pincer, en
particulier au niveau de la prise, et aux endroits où il sor de
l’appareil.
11. N’utilisez que des accessoires spécifiés par le constructeur.
Suite de la page suivante
9
Important Safety Instructions
12. N’utilisez qu’avec un stand, ou table conçus pour l’utilisation
d’audio professionnel ou instruments de musique. Dans toute
installation, veillez de ne rien endommager à cause de câbles
qui tirent sur des appareils et leur support.
13. Débranchez l’appareil lors d’un orage ou lorsqu’il n’est pas
utilisé pendant longtemps.
14. Faites réparer par un personnel qualifié. Une réparation est
nécessaire lorsque l’appareil a été endommagé de quelque sorte
que ce soit, par exemple losrque le cordon secteur ou la prise
sont endommagés, si du liquide a coulé ou des objets se sont
introduits dans l’appareil, si celui-ci a été exposé à la pluie ou à
l’humidité, ne fonctionne pas normalement ou est tombé.
15. Puisque son fonctionement normale génère de la chaleur,
placez cet appareil au moins 15cm. des équipments
péripheriques et assurez que l’emplacement permet la
circulation de l’air.
16. Ce produit, utilisé avec un amplificateur et un casque ou des
enceintes, est capable de produite des niveaux sonores pouvant
engendrer une perte permanente de l’ouïe. Ne l’utilisez pas
pendant longtemps à un niveau sonore élevé ou à un niveau
non confortable. Si vous remarquez une perte de l’ouïe ou un
bourdonnement dans les oreilles, consultez un spécialiste.
17. N'exposez pas l'appareil à l'égoutture ou à l'éclaboussement.
Ne placez pas les objets remplis de liquides (vases à fleur,
boîtes de boisson non alcoolique, tasses de café) sur l'appareil.
18. AVERTISSEMENT: Pour réduire le risque du feu ou de
décharge électrique, n'exposez pas cet appareil à la pluie ou à
l'humidité.
19. Quand ce produit est en fonction, l'alimentation secteur peut
provoquer des interférences sur la fonction surround. Une
fois installé, si vous détectez que le produit ne fonctionne pas
correctement, le problème peut être résolu en effectuant un
reset de l'appareil ( débrancher l'alimentation et rebrancher la
après quelques secondes ) ou insérez l'alimentation de
l'appareil dans une prise secteur équipée d'une masse correcte.
10
Important Safety Instructions
Lesen Sie bitte die folgende Sicherheitshinweise (German)
Sicherheit Symbole verwendet in diesem
Produkt
Dieses Symbol alarmiert den Benutzer, daß es wichtige
Funktionieren und Wartung Anweisungen in der Literatur gibt, die
diese Maßeinheit begleitet.
Dieses Symbol warnt den Benutzer der nicht isolierten
Spannung innerhalb der Maßeinheit, die gefährliche elektrische
Schläge verursachen kann.
Dieses Symbol warnt den Benutzer, dem Ausgabestecker
Spannungen enthalten, die gefährlichen elektrischen Schlag
verursachen können.
Folgen Sie bitte diesenVorkehrungen, wenn
dieses Produkt verwendet wird:
1. Lesen Sie die Hinweise.
2. Halten Sie sich an die Anleitung.
3. Beachten Sie alle Warnungen.
4. Beachten Sie alle Hinweise.
5. Bringen Sie das Gerät nie mit Wasser in Berührung.
6. Verwenden Sie zur Reinigung nur ein weiches Tuch.
Verwenden Sie keine flüssigen Reinigungsmittel. Dies kann
gefährliche Folgen haben.
7. Halten Sie sich beim Aufbau des Gerätes an die Angaben des
Herstellers.
8. Stellen Sie das Gerät nich in der Nähe von Heizkörpern,
Heizungsklappen oder anderen Wärmequellen (einschließlich
Verstärkern) auf.
9. Verfehlen Sie nicht den Zweck des grounging Terminals auf
dem Netzstecker. Dieses Terminal wird für Ihre Sicherheit zur
Verfügung gestellt.
10. Verlegen Sie das Netzkabel des Gerätes niemals so, daß man
darüber stolpern kann oder daß es gequetscht wird.
11. Benutzen Sie nur das vom Hersteller empfohlene Zubehör.
Fortsetzung auf nächster seite
11
Important Safety Instructions
12. Verwenden Sie ausschließlich Wagen, Ständer, oder Tische, die
speziell für professionelle Audio- und Musikinstrumente
geeignet sind. Achten Sie immer darauf, daß die jeweiligen
Geräte sicher installiert sind, um Schäden und Verletzungen zu
vermeiden. Wenn Sie einen Rollwagen benutzen, achten Sie
darauf, das dieser nicht umkippt, um Verletzungen
auszuschließen.
13. Ziehen Sie während eines Gewitters oder wenn Sie das Gerät
über einen längeren Zeitraum nicht benutzen den Netzstecher
aus der Steckdose.
14. Die Wartung sollte nur durch qualifiziertes Fachpersonal
erfolgen. Die Wartung wird notwendig, wenn das Gerät
beschädigt wurde oder aber das Stromkabel oder der Stecker,
Gegenstände oder Flüssigkeit in das Gerät gelangt sind, das
Gerät dem Regen oder Feuchtigkeit ausgesetzt war und
deshalb nicht mehr normal arbeitet oder heruntergefallen ist.
15. Dieses Gerät produziert auch im normalen Betrieb Wärme.
Achten Sie deshalb auf ausreichende Lüftung mit mindestens
15 cm Abstand von anderen Geräten.
16. Dieses Produkt kann in Verbindung mit einem Verstärker und
Kopfhörern oder Lautsprechern Lautstärkepegel erzeugen, die
anhaltende Gehörschäden verursachen. Betreiben Sie es nicht
über längere Zeit mit hoher Lautstärke oder einem Pegel, der
Ihnen unangenehm is. Wenn Sie ein Nachlassen des Gehörs
oder ein Klingeln in den Ohren feststellen, sollten Sie einen
Ohrenarzt aufsuchen.
17. Setzen Sie den Apparat nicht Bratenfett oder dem Spritzen
aus. Plazieren Sie die Nachrichten, die mit Flüssigkeiten
(gefüllt werden Blumevases, Getränkdosen, Kaffeetassen)
nicht auf den Apparat.
18. WARNING: um die Gefahr des Feuers oder des elektrischen
Schlages zu verringern, setzen Sie diesen Apparat nicht Regen
oder Feuchtigkeit aus.
19. Das Netzteil des Audiogerätes kann Interferenzstörungen der
Umgebung ausgesetzt sein. Sollten nach erfolgter Installation
Fehlfunktionen am Gerät auftreten, können diese durch ein
Zurücksetzen des Gerätes (Reset), durch einen anderen
Aufstellungsortes des Gerätes oder durch den Einsatz eines
Spannungsstabilisators behoben werden.
12
Important Safety Instructions
CE Declaration of Conformity
See our Web site at:
FCC Compliance Statement
This device complies with Part 15 of the FCC rules. Operation is
subject to the following two conditions: (1) This device may not
cause harmful interference and (2) this device must accept any
interference received, including interference that may cause
undesired operation.
NOTE: This equipment has been tested and found to comply with
the limits for a Class B digital device, pursuant to Part 15 of the
FCC Rules. These limits are designed to provide reasonable
protection against harmful interference in a residential installation.
This equipment generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the
instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference
will not occur in a particular installation. If this equipment does
cause harmful interference to radio or television reception, which
can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one or more of
the following measures:
-- Reorient or relocate the receiving antenna.
-- Increase the separation between the equipment and receiver.
-- Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.
-- Consult the dealer or an experienced radio/TV technician for
help.
13
Important Safety Instructions
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14
1 Quick Start Guide
If you can’t wait to get started…
The Alesis DEQ830 is a unique product, but its basic hookup and
operation are similar to other equalizers in most respects. If you're
experienced with signal processors, this chapter is a “shorthand”
guide for those who want to start using the DEQ830 right away. If
you have questions about any of the features, don’t worry – all the
details will be covered in later chapters.
If you're new to signal
processing, start with the
more detailed instructions for
hookup and operation found
in the next chapter.
Step 1: Hook it up to a mixer
The DEQ830’s power will
turn on automatically once its
AC cable is plugged in, so be
sure to press the [POWER]
switch to turn the unit off
while you’re connecting it to
your other equipment.
1. Plug the POWER jack on the back of the DEQ830 into a
grounded AC power source with the supplied power cable.
2. Using high-quality cables, plug the left and right main outputs
of a non-powered mixer into the Channel 1 and Channel 2
inputs on the back of the DEQ830. You may connect up to
eight separate audio sources in the same manner.
3. Connect another pair of cables to the Channel 1 and Channel
2 outputs of the DEQ830 and plug them into your
amplification system or a pair of powered monitors.
4. Press the [POWER] switch on the front of the DEQ830 to
power up the unit.
When connecting the
5. You may want to link some of the channels together—
Channels 1 and 2, for example. That way you’ll hear the
changes you make with Channel 1 affect both channels of
the stereo signal at once. To do so, select Channel 1 by
pressing its [CHANNEL SELECT] button. Then hold
down the [LINK] button and press Channel 2’s
[CHANNEL SELECT] button at the same time. After this,
any EQ changes you make to Channel 1 will be reflected in
Channel 2. You may link up to eight channels together using
this method.
DEQ830 to other equipment,
make sure all gear has been
turned off. Also, to protect
your speakers, be certain
your amplifier(s) are turned
all the way down before
turning your equipment back
on.
15
1 Quick Start Guide
Step 2: Try some equalization
Play some signal into the unit
While learning the unit, you should play a CD or a multitrack
source into the equalizer. Choose a song or musical passage with a
fairly consistent level, so you can take your time experimenting
with the different features.
1. Put the mixer’s main faders all the way down so you don’t
distort the unit by sending it too much signal.
At the factory, we set all of
Program 00’s frequencies to
0 dB. It’s a good idea to leave
Program 00 this way, but if
you have already overwritten
it with some of your own
settings, you can just create
your own program with
2. Select program 00 on the DEQ830. This will call up a
program with all frequencies set to 0 dB, allowing you to hear
the changes you make to the audio more easily.
3. Begin playing your source material. Bring the mixer’s main
faders up gradually until the Channel Meters for Channels 1
and 2 begin to light up. Carefully increase the mixer’s output
level until the meters’ green and yellow LEDs are lit most of
the time. If the red CLIP LEDs at the top of the meters light
up at all, back the mixer’s output level down until they stop
lighting up. This is important, because these red LEDs indicate
that the signal is clipping on that channel.
“flat” settings for the
purposes of this experiment.
Remember: if the red CLIP
LED at the top of a Channel
Meter lights up, that means
the signal is clipping. To
prevent this, reduce the level
being sent to the proper
channel.
4. Press one of the [BAND SELECT] buttons to select a
frequency. One of the LEDs above that button will begin to
blink.
5. Use the [VALUE] encoder to decrease or increase the chosen
frequency. If desired, select another frequency and repeat this
process.
6. Press the [BYPASS] button to hear the signal without the
equalization effect. Press it again to return to the EQ’d signal.
7. Repeat steps 3 – 6 for the other audio sources you have
connected to the DEQ830.
Step 3: Store the Program
Once you have created an interesting program, you can save it to
one of the 100 user program locations. Here’s how to do this:
Programs 25-99 have been
left blank so you have
somewhere to store your
programs right away without
overwriting the factory
presets.
1. Press the [STORE] button to enter Store mode.
2. Use the [VALUE] encoder to select the new location for the
edited program. For your convenience, programs 25-99 have
been left blank so you can store your editing experiments
somewhere without fear of overwriting a program you might
want to use later.
3. Press the [VALUE] encoder to store the program to the new
location. This will preserve the EQ settings for all eight
channels of audio.
16
Quick Start Guide 1
Step 4: Save an EQ Curve
In addition to being able to save entire programs, you can also save
the settings for an individual EQ curve. Here’s how to do this:
1. Select the curve you wish to save by pressing that channel’s
[CHANNEL SELECT] button.
2. Press the [SAVE CURVE] button to enter Save Curve mode.
3. Use the [VALUE] encoder to select the new location for the
edited curve. For your convenience, curves 50-99 have been
left blank so you can save your editing experiments somewhere
without fear of overwriting a curve you might want to use
later.
4. Press the [VALUE] encoder to save the curve to the new
location. You can retrieve any one of the 100 curves for use in
any of the DEQ830’s 100 programs.
17
2 Connections
Unpacking and Inspection
Your DEQ830 was packed carefully at the factory. The shipping
carton was designed to protect the unit during transit. Please keep
this carton in the highly unlikely event that you need to return the
DEQ830 for servicing.
The shipping carton should contain the following items:
•
DEQ830 with the same serial number as shown on the
shipping carton
•
•
AC power cable
This instruction manual
Installing in a Rack
The DEQ830 may be simply set on a table, or installed in a
standard 19" audio equipment rack.
Thermal Considerations in Rack
Mounting
The DEQ830 can be mounted in an equipment rack (occupying
one rack space) or placed on a table or shelf. When you install it,
keep in mind that heat is the greatest enemy of electronic
equipment. Please observe the following:
•
•
The DEQ830 is designed to perform properly over a range of
ambient temperatures from 10° C to +40° C (50° F to 104° F),
in up to 80% non-condensing humidity. These are not absolute
limits, but Alesis cannot guarantee that the DEQ830 will meet
its published specs or remain reliable if operated outside of
these ranges.
Always allow adequate ventilation behind the DEQ830. Do not
seal any enclosure that holds this unit. It is not necessary to
leave an empty rack space above or below the DEQ830.
However, if your environment is unusually warm and not air
conditioned, space between units will help the units run cooler.
19
2 Connections
AC Power Hookup
The DEQ830 has what’s known as a “switching power supply.”
This means it will detect any standard line voltage from 90 to 230
volts, 50-60 Hz, and adapt itself to that. All you need is the proper
AC cable for the country in which you find yourself. Just plug the
"female" end of the power cable into the DEQ830’s POWER
receptacle and the “male” end into a good quality, noise-free AC
power source.
Using the DEQ830 in another country
Your DEQ830 was supplied with the correct power cord for your
country or local area. If you plan to travel with it to another
country, obtain an Alesis AC power cord compatible with the
outlets used in the other country and use it in place of the supplied
cord. These can be obtained through your Alesis dealer or through
the Alesis Parts department.
20
Connections 2
Connecting Inputs and Outputs
Connecting to the Channel or Main Inserts
of a mixing console
Unbalanced I/O
When connecting audio
cables and/or turning power
on and off, please make sure
that your amplifiers are
turned down or off to prevent
damage to your speakers.
Most mixing consoles have insert jacks near the main outputs and
for each channel as well. These are typically Tip-Ring-Sleeve (TRS)
jacks with the send and return on the same jack. To use the
DEQ830 as an effects insert device, you will need an insert cable
(not included).
This cable splits the TRS insert jack into two unbalanced mono
connectors. Usually, the tip is wired to the “Send” connector,
which plugs into one input of the equalizer, and the ring is wired
to the “Return” connector, which plugs into the corresponding
output of the equalizer. However, the wiring of the insert jacks is
different on some recording consoles, which means that the
input/output relationship may be reversed. Check your mixer’s
Reference Manual to be sure, or just try it both ways – this won’t
damage the DEQ830.
If your mixer does not have
insert jacks available at its
main outputs, simply connect
the main outputs of your non-
powered mixer to the inputs
of the DEQ830, then connect
the outputs of the equalizer to
the inputs of your mixdown
recorder or amplified
monitoring system.
21
2 Connections
Mono connections
This example shows how to connect the DEQ830 to one mono
source. You can use this method to connect eight mono sources to
the DEQ830. You would need eight insert cables to make all of
these connections.
Since the DEQ830 has eight
channels, you can connect
eight independent sources.
For example, you could use
Channel 1 to EQ the rhythm
guitar, Channel 2 to EQ the
bass guitar, Channels 3 and 4
to EQ the left and right
outputs of a keyboard, and so
on.
Stereo connections
Use two insert cables to connect the DEQ830 to the main L/R
bus in the same way you would connect it to a pair of channel
inserts. Simply connect one insert cable to the left main insert of
the mixer, and connect the two mono jacks to the Channel 1 input
and output of the DEQ830. Use another insert cable to connect
the right main insert to the Channel 2 input and output of the
DEQ830.
You can also simply connect the balanced main outputs of the
mixer to the inputs of the DEQ830, then connect the outputs
of the equalizer to the inputs of your mixdown recorder,
monitor system, etc.
Never place the equalizer
between the power amp and
the speakers, as the high-
powered levels created by the
power amp will damage the
DEQ830.
Balanced I/O
Some recording consoles have separate balanced jacks for the
sends and returns instead of a single TRS jack. If your recording
console has these connections, use a balanced TRS cable to
connect the insert send to the input of the equalizer, and another
balanced TRS cable to connect the equalizer output to the insert
return.
Modern production values
sometimes lead to the heavy
use of compression during the
mastering process. When
processing CD audio, you
may find it necessary at times
to lower the Channel Level of
the active program so as to
avoid clipping the output
stage of the DEQ830. This
will allow additional
Operating Levels
The DEQ830 can operate in either a +4dBu or –10dBV setting. A
rear panel switch allows you to configure the unit to your audio
environment.
headroom for more extensive
equalization. See pg. 32 for
details on the Channel Level
function.
If you are unsure about the nominal operating level of the
equipment to which you will be connecting the DEQ830, refer to
the Reference Manual for that equipment.
22
Connections 2
Connecting to the inserts on an instrument
amplifier
Unbalanced I/O
The insert sends on a guitar or bass amp are usually labeled
“effects send and return” or “insert send and return.” This allows
your instrument to be boosted to line level before the signal is sent
to the equalizer, processed, and returned to the power amp.
If you are using a two-piece system, another method would be to
insert the DEQ830 between the preamp and the power amp. You
should never put the equalizer between the power amp and the
speaker, as the high-powered levels created by the power amp will
damage the unit.
Connecting to equipment with XLR inputs
and outputs
Don't use line transformers!
Many XLR-to-1/4" adapters
sold at electronics stores are
NOT adapters, but
transformers (and very low
quality transformers at that).
Don't use these on the output
of the DEQ830—they're
If you are connecting the DEQ830 to a product with XLR
balanced inputs and outputs, you will need to convert this signal to
a TRS balanced connector. Make sure that pin 2 of the XLR
connector is connected to the tip of the TRS adapter, and pin 3 is
connected to the sleeve.
unnecessary and generally
sound awful because they
don't have the headroom to
handle the DEQ830's output.
Get a hard-wired adapter or
cable from your professional
audio dealer, or make one
yourself from components.
Connecting to equipment with ADAT Optical
inputs and outputs
The DEQ830 has the capability of receiving and transmitting its
audio signal in the digital domain. This is done through a pair of
ADAT Optical jacks found on the rear panel. The jacks are labeled
ADAT Optical In/Out. Each carries eight channels of audio, so all
eight of the DEQ830’s channels are handled by a single cable in
each direction.
Using the ADAT Optical jacks to connect to an external device
such as the Alesis ADAT HD24 is very easy, because the DEQ830
will automatically switch over to the ADAT Optical inputs when it
senses that a valid digital signal is present.
There are three ways to connect the DEQ830 with another digital
audio device, as explained on the next page.
23
2 Connections
Analog Signal In, Digital Signal Out
In this configuration, the DEQ830 can be used to “translate” an
analog signal to the digital domain. A likely scenario would be
using the DEQ830 as an analog-to-digital converter between your
submix outputs and an Alesis ADAT. In addition to acting as a
“gateway,” the DEQ830 would allow you to shape the sound and
send it to the ADAT digitally, without the additional noise that can
be added by an analog EQ.
Digital audio offers a decided
advantage over analog audio
when passing the signal
through multiple devices. The
various stages of analog
circuitry can cause the
To use the DEQ830 in this way, connect the ADAT Optical
output of the DEQ830 to the ADAT Optical input of the
receiving device.
Digital Signal In, Analog Signal Out
quality of the signal to
deteriorate rapidly; however,
once a signal has been
In this setup, the DEQ830 also serves as a signal converter,
making it possible to take the digital submix outputs of an 8-bus
mixer, apply some EQ and then send the result as an analog signal
into a sound system— the Alesis ProActive 5.1 Surround Sound
System, for example, or a series of independent onstage monitors.
converted to the digital
domain, it can be carried
from device to device with a
minimal loss of integrity. This
is why it is advantageous to
pass the signal through the
DEQ830 using its ADAT
Optical jacks whenever
possible.
If an analog mixer has limited channel EQ capabilities, you could
run the digital signal from an ADAT into the DEQ830, and from
there take it to your mixer’s analog inputs. This would allow you to
take advantage of the DEQ830's extensive EQ and simply use the
mixer for setting the levels and pan positions of the signals.
For these situations, be sure to connect the ADAT Optical output
of the transmitting device to the ADAT Optical input of the
DEQ830.
Digital Signal In, Digital Signal Out
In cases where every device in your audio chain has a digital audio
input and output, the DEQ830 is right at home. Simply pass the
audio from the transmitting device’s ADAT Optical output into
the DEQ830’s ADAT Optical input, use it to sculpt the signal, and
then pass the audio on to the next device by connecting the
DEQ830’s ADAT Optical output to the ADAT Optical input of
the receiving device.
Operating the DEQ830 in any of the three configurations
described above is really no different from using it in a completely
analog system. For that reason, from this point on in the manual
we will make no distinction between operating the DEQ830 in the
digital or analog domains.
24
Connections 2
About Audio Cables
The connections between the DEQ830 and your studio are your
music’s lifeline, so use only high quality cables. These should be
low-capacitance shielded cables with a stranded (not solid) internal
conductor and a low-resistance shield. Although quality cables cost
more, they do make a difference.
Route cables to the DEQ830 correctly by
observing the following precautions:
•
•
Do not bundle audio cables with AC power cords.
Avoid running audio cables near sources of electromagnetic
interference such as transformers, monitors, computers, etc.
Do not place cables where they can be stepped on. Stepping on
a cable may not cause immediate damage, but it can compress
the insulation between the center conductor and shield,
degrading the cable’s performance and reducing the cable’s
reliability.
•
•
•
Avoid twisting the cable or having it make sharp, right angle
turns.
Never unplug a cable by pulling on the wire itself. Always
unplug by grasping the body of the plug firmly and pulling
directly outward.
And most importantly, keep connectors clean. Every few months,
unplug them and wipe off oxidation with a clean cloth soaked in
alcohol or contact cleaner. Insert the plugs into the jacks a few
times to clean the internal jack contacts.
Although Alesis does not endorse any specific product, chemicals
such as Tweek (also known as Stabilant) and Cramolin, when
applied to electrical connectors, are claimed to improve the
electrical contact.
25
2 Connections
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26
3 Basics of Equalization
This section will describe how equalization works and explain the
functions of the DEQ830’s controls.
What is equalization?
An equalizer boosts or cuts a frequency range. The DEQ830 is a
graphic equalizer, which means it has many fixed frequency bands
that can be cut or boosted. The term “graphic” is appropriate
because the combined settings of the bands often resemble a
curve, or “graph.” Thus, it is often possible to know what the unit
is doing to the sound simply by looking at it from a distance. The
other type of equalizer, a parametric equalizer, can sweep the
frequency bands and adjust the frequency range affected by the cut
or boost of each band. Alesis sells a parametric equalizer called the
PEQ-450.
The most basic level of control on a graphic equalizer is the gain
setting for a band. Each of the bands represents a predetermined
frequency range, and its gain setting controls the amount of boost
or cut for that frequency range. A setting of 0 dB means that the
signal will not be affected in the area of those audio frequencies.
Depending on the program material, boosting or cutting just one
frequency can have a significant impact on the sound. When all of
the frequency bands are taken together, the impact can be huge.
Equalization can be used for:
•
•
Adjusting the timbre of an instrument, voice, mix, or effect
Cutting or boosting frequencies to make a source easier to mix
with other tracks
•
•
Compensating for a less-than-ideal recording
Compensating for less-than-ideal control room or auditorium
acoustics
•
•
Creating a filter effect
Eliminating buzz, noise, or hum
Equalizers can make your recorded tracks sound polished and
professional. Chapter 4 will describe some specific settings for
various instruments and applications.
27
3 Basics of Equalization
Description of the Front Panel
This section will give you an overview of the front panel’s features.
Not all features are labeled, so you may want to refer to the
Band Select
There are 31 buttons side-by-side on the left half of the
DEQ830’s front panel. The first 30 are the [BAND SELECT]
buttons. Above each of the [BAND SELECT] buttons is a
number like “25” or “8k.” These stand for the audio frequencies,
measured in Hertz (Hz), which are selected for editing by the
[BAND SELECT] buttons below them. The 31st button is the
[CHANNEL LEVEL] button, which is explained below.
Channel Level
For details on the
The [CHANNEL LEVEL] button is used to set the level of the
currently selected channel or Link Group. This setting is post-EQ
and pre-Master Level.
relationship between Master
Level and Channel Level, see
RealTime Analyzer (RTA)
This button will put the DEQ830 into Real Time Analyzer
mode, in which the unit serves as a visual aid for analyzing the
audio signal. In this mode, the Band Gain LEDs “dance to the
music,” displaying the relative strengths of the various frequency
ranges passing through the DEQ830. For more on this mode, see
page 43.
Channel Select
To the right of the [POWER] button, you’ll see the
[CHANNEL SELECT] buttons. These eight buttons are used
for selecting a channel for which the EQ settings will be displayed
on the 30 Band Gain LEDs. The [CHANNEL SELECT]
buttons are also used for creating Link Groups.
Monitor Select (INPUT/OUTPUT)
This button, located immediately above the [BYPASS] and [ALL]
buttons, toggles between INPUT and OUTPUT to determine
whether the Channel Meters and RTA display the input or output
levels. The green LEDs above this button indicate which
monitoring method is currently selected.
Bypass mode “hides” the
effect of the EQ and Channel
Level controls on the audio.
However, the Master Level
function from Utility mode is
unaffected by the [BYPASS]
button. For more information
about the relationship
Bypass
When you press this button, a red LED will light immediately
above the currently selected channel, indicating that this channel is
in Bypass mode. As long as this LED is lit, incoming audio will
pass through this channel without being affected by its EQ settings.
Also, if you’re on a linked channel when you press the [BYPASS]
button, all of the linked channels will bypass at the same time.
Bypass mode is useful for comparing the “equalized” signal with
between Channel Level and
28
Basics of Equalization 3
the original signal so you can decide if you like the edit you made.
Press the button again to get out of Bypass mode and hear the
effect.
Bypass All (ALL)
This button is located just above the [BYPASS] button. It will
toggle the Bypass status of all eight channels at once. The first
press of the [ALL] button will cause any unbypassed channels to
enter Bypass mode. Subsequent presses will toggle the Bypass
status of all eight chanels together. The red LEDs below each
channel meter will light to indicate that the channels are bypassed.
Link (PUSHTO LINK)
This button is used to link channels together so that their EQ
settings are locked together. Any edits you make to a band on one
channel will also be applied to that same band on all linked
channels. This is useful for quickly setting up a program without
having to make independent adjustments for each channel.
Store
Once you have created a program you would like to keep, press
this button to enter Store mode. From there you can use the
[VALUE] encoder to select one of the 100 memory locations to
become the new home for the edited program. For more
Compare
This button will help you if you are editing a program and would
like to hear how the program sounded before you edited it.
Pressing this button will temporarily recall the original program,
and pressing it a second time will restore the edited program. The
green LED above this button will light to indicate that the Band
Gain LEDs are now showing the EQ curve as it appeared before
your edits.
When you press
[COMPARE], the stored
settings for all eight channels
of the current program are
temporarily recalled.
Utility
If you press [UTILITY] while you are in Program mode, you will
enter Utility mode, which lets you edit the Master Level, MIDI
Settings, the internal clock rate and other global parameters. If you
hold down this button at startup as the DEQ830’s splash screen is
displayed, you will enter Lock mode. This mode allows you to lock
the front panel buttons. For more information on Utility mode, see
page 50.
Save Curve
Press [SAVE CURVE] to save a channel’s EQ curve to the
DEQ830’s curve bank so that it can be retrieved at a later time.
We’ve provided 100 locations (00-99) in which to save curves.
Curves 00-49 contain factory presets, and curves 50-99 are blank.
Any of the 100 curves may be modified and saved. For more
information on saving curves, see page 40.
29
3 Basics of Equalization
Program
If you want to cancel any action in progress and return to
Program mode, just press the [PROGRAM] button.
Value Encoder (VALUE)
On far right side you’ll find a knob marked [VALUE], which is
used to edit the gain amount of the frequency you have selected
with the [BAND SELECT] buttons. (It is also possible to select
and edit several frequencies at once, as you’ll see later.) The
[VALUE] encoder is also used for all sorts of data entry, such as
selecting programs and curves, changing global parameter values
and so forth. Changes made with the [VALUE] encoder are
reflected in the Numerical LED Display to the left of the knob.
Numerical LED Display
The three-digit LED display you see to the left of the [VALUE]
encoder is always showing either a value or an abbreviated name.
To help you know at a glance what sort of information the display
is giving you, there are three green LEDs immediately below the
Numerical LED Display:
PROG
If this LED is lit, this means the value in the
display is a program number. You will see this
when the unit is in Program mode or Store
mode.
CURVE
dB
When lit, this LED indicates that the number
in the display is telling you which curve has
been chosen.
This LED tells you that the value in the
display pertains to a gain change.
The only time that none of these LEDs will be lit is when the
DEQ830 is in Utility mode.
30
Basics of Equalization 3
Description of the Basic Modes
Program mode
When this manual refers to Program mode, we mean the very top
level of functionality of the DEQ830. In program mode, turning
the [VALUE] encoder will let you select between the 100 user-
definable preset programs in the unit.
A program consists of more than just EQ settings. The things
stored in memory and recalled when you select a program are:
•
•
•
The gain settings of all 30 bands for channels 1 – 8
The Link status of all 8 channels
The actual gain settings for all non-primary channels in a Link
Group. These are merely “hidden” by the Link function.
•
The individual Channel Level settings for channels 1 – 8
If the DEQ830 has been in some other mode, pushing the
[PROGRAM] button will return it to Program mode. If the LED
above the [STORE] button is flashing, that means the program
has been edited. If you’ve made any changes that you would like to
keep, be sure to save them before switching to another program!
Edit mode
While in Program mode, pushing one of the [BAND SELECT]
buttons will take you to Edit mode. You can tell you are in Edit
mode when one or more of the LEDs above the [BAND
SELECT] buttons are blinking. The bands with blinking LEDs
are the ones that will be boosted or cut when you turn the
[VALUE] encoder.
After you have edited a frequency or an Edit Group (a group of
frequencies), pushing the [PROGRAM] button will return you to
Program mode. If you’ve made any changes, the LED above the
[STORE] button will be flashing. Be certain to save any changes
that you would like to keep! This is where Store mode comes in.
Store mode
Pressing the [STORE] button takes you to Store mode. From
here you can decide which of the 100 program locations will
become the new home for the edited program. For information on
Save Curve mode
Pressing the [SAVE CURVE] button takes you to Save Curve
mode. This lets you save an edited EQ curve to one of the 100
memory locations in the DEQ830’s curve bank. These curves can
be recalled later and applied to any channel of any program. You
can use the Curve Bank to save templates for all possible EQ
applications. For example, you can save an EQ curve that generally
31
3 Basics of Equalization
Curve 00 is a “flat” curve.
We recommend that you
leave Curve 00’s gain
settings at 0 so that you may
use it as a “clean slate” for
building new curves from the
ground up.
works well for male vocals. Say you have two or three channels of
male vocals feeding into the DEQ830. To EQ these, just retrieve
the curve from the Curve Bank, apply it to each male-vocal
channel and modify it slightly to fit each particular vocal.
Retrieve Curve mode
This mode allows you to take a stored EQ curve from the Curve
Bank and place it into the currently selected channel or Link
Group. For information on how to do this, see page 41.
Bypass mode
This mode is nearly as simple as it sounds—pushing the
[BYPASS] button will let you hear the non-equalized audio. But
there’s a bit more to it than that. There are also two gain
adjustment stages that can be used to compensate for a reduction
or increase in signal level caused by the equalization curve being
used. The value for one of these stages, Channel Level, is saved
along with the EQ settings when the program is stored; the value
for the other stage, Master Level, is not. So what Bypass mode
really is doing is causing the audio to “pass by” the processing
stages that are stored as a part of the program.
You’ll find a description of
Channel Level mode further
down on this page. For a
description of the Master
Level function, turn to page
The following diagram shows the relationship between each of the
stages in the DEQ830’s signal processing chain.
Channel Level mode
When you run a number of different instruments into the
DEQ830, each channel may experience drastically different signal
levels. Channel Level mode can be used to adjust the output of
each channel independently.
Unlike the Master Level
function in Utility mode, the
settings for Channel Level
mode are stored with each
curve or program. For more
on Channel Level mode, see
This mode is also useful when processing a stereo signal. If the
combination of the source material and extreme EQ settings is
causing the output of the DEQ830 to clip, Channel Level mode
can be used to adjust the output of two stereo channels
simultaneously. To do this, the two channels must be linked. See
32
Basics of Equalization 3
Link mode
In this mode, you can link multiple channels so that their EQ
settings are locked together. To experiment with this, first select a
channel with recognizable settings. Next, press and hold down the
[LINK] button. You can then select channels to link to the
original channel by pressing their [CHANNEL SELECT]
buttons. You will see the Band Gain LEDs for each linked channel
change to match the settings of the currently selected channel.
(But don’t worry—the original settings are still retained in
memory; more about that later.)
Utility mode
This is the mode you’ll enter when you hit the [UTILITY] button.
Here you can adjust a number of global settings that determine
how the DEQ830 behaves.
For details on Utility mode, turn to page 45.
RealTime Analyzer mode
In this mode, the DEQ830 will display an animated representation
of the frequencies found in the audio signal passing through the
unit. When you press [RTA], the Band Gain LEDs will begin to
rise and fall as the frequencies of the signal peak and dip.
This mode also allows you to visually compare the audio signal
before and after it is processed by the DEQ830. For more on Real
Time Analyzer mode, see page 43.
33
3 Basics of Equalization
Basic operation: Program mode
Program mode is where to be if you want to call up another
program, or if you just want to know the number of the program
you are using. The DEQ830 has 100 programs in all. Programs 00-
24 contain factory presets that you can use as starting points for
your own programs. You can overwrite any of the 100 programs.
If the program number
flashes when you try to select
another program, this means
that the Fast Program Select
feature is off, and you will
need to press the encoder to
enfirm the program change.
For more information, see
pages 44 and 47.
Navigation in Program mode is a breeze. First, if you’re not in
Program mode, get there by pressing the [PROGRAM] button.
The Numerical LED Display will show you the number of the
current program. All you have to do to call up a new program is
turn the [VALUE] encoder. This enables you to quickly reach any
program in the unit's memory.
Basic operation: Edit mode
If you're not already there, exit to Program mode by using the
[PROGRAM] button. Then select Program 00 on the DEQ830
by using the [VALUE] encoder.
Just as Program 00 is a
“flat” program, Curve 00 is a
“flat” curve. We strongly
recommend that you leave
Curve 00’s gain settings at 0
so that you may use it as a
“clean slate” for building
new curves from the ground
up.
The original factory Program 00 is a “flat” program, and it’s
easy to see why it’s called that—the gain setting for every band
is 0 dB. Calling up this program is almost the same as pressing
the Bypass button, in that the audio passing through the unit
will not be equalized in any way. Of course, the difference is that
you can edit the program and hear the changes that you make. If
you don’t already know what kind of EQ you're looking for, this
may be a good place to start.
Single Band Edit
Pressing a [BAND SELECT] button puts the DEQ830 into Edit
mode. The Numerical LED Display will now display the gain value
in decibels (dB) of the band you just selected. In addition, one of
the Band Gain LEDs above that [BAND SELECT] button will
start blinking. If the gain value of that band is 0 dB, the green
LED will blink. This means there is no gain change occurring in
this frequency range. If it is higher or lower than that, one of the
yellow LEDs will blink. This indicates that some amount of cut or
boost is happening.
Use the [VALUE] encoder to change the gain value of that band.
Turning the [VALUE] encoder left will lower the gain value, or
“cut” the chosen frequency; turning it right will raise the gain
value, or “boost” the frequency. There is an overall range of
+/- 12 dB of gain change available.
34
Basics of Equalization 3
Band Solo
The DEQ830 has a handy feature called Band Solo that allows you
to “isolate” a given frequency while you are editing. This can help
you determine exactly which band you need to highlight or de-
emphasize. It’s simple to do:
1. Select a band by pressing and holding its [BAND SELECT]
button.
2. Press the [VALUE] encoder. You’ll see the LED for that
band jump to +12 dB.
3. Press the [VALUE] encoder again. The LED for that band
will jump to –12 dB.
4. Release the [BAND SELECT] button, and the value of that
band will be returned to its original setting.
This only works with one band at a time, but you’ll find it to be a
very helpful feature.
If you want to keep an edited
curve or program, be sure to
store it. For instructions on
how to do this, turn to page
To exit Edit mode, press the [PROGRAM] button. This will
return the DEQ830 to Program mode.
Band Gain Cut/Boost Ranges
Whether you are cutting or boosting a band, gain change happens
in 0.5 dB increments. As you make the change, the Numerical
LED Display will show you the magnitude of the gain: 0.5, 1.0,
1.5, 2.0, ... up to 12.0.
Because it’s not possible to show a minus sign in the LED display
for negative gain values, you’ll see the same sequence as you turn
the encoder to the left. But if there’s any doubt in your mind about
which way you’re going, the Band Gain LED will clue you in. As
soon as you move 0.5 dB away from 0, the LED for that band will
change from green to yellow. If you are cutting the frequency,
you’ll see a yellow light below the center line. If you are boosting
it will be above.
Since the front panel only has thirteen gain LEDs to represent the
49 possible levels of gain in each band, you may not see the LED
change when you make small adjustments to the gain. The table on
the following page shows the amount of change in dB it takes to
light each of the Band Gain LEDs:
35
3 Basics of Equalization
LED
Gain Change
11.5 – 12.0 dB
9.5 – 11 dB
7.5 – 9.0 dB
5.5 – 7.0 dB
3.5 – 5.0 dB
0.5 – 3.0 dB
0 dB
+ 12 dB
+ 10 dB
+ 8 dB
+ 6 dB
+ 4 dB
+ 2 dB
0 dB
- 2 dB
- 4 dB
- 6 dB
- 8 dB
- 10 dB
- 12 dB
0.5 – 3.0 dB
3.5 – 5.0 dB
5.5 – 7.0 dB
7.5 – 9.0 dB
9.5 – 11 dB
11.5 – 12.0 dB
36
Basics of Equalization 3
Multiple Band Edit
Selecting an Edit Group
Pressing a [BAND SELECT] button puts the DEQ830 into Edit
mode. And until you turn the [VALUE] encoder to boost or cut
the gain, you can keep pressing [BAND SELECT] buttons until
you have several of them selected simultaneously. This is called
selecting an Edit Group. An Edit Group can be made up of any
number of bands. Another way to select an edit group is to hold
down a [BAND SELECT] button and turn the encoder. This
will allow you to select a range of bands at once.
There’s an easy way to create
an Edit Group from multiple
adjacent bands. Just press
and hold a [BAND
SELECT] button as you spin
the [VALUE] encoder left or
right. The farther you spin the
encoder, the more bands you
will select. After you release
the [BAND SELECT] button,
you can use the encoder to
adjust the gain of all selected
bands at once.
The Relative Gain display
When you pressed the first [BAND SELECT] button, two things
happened: the Numerical LED Display changed to show the gain
value of that band, and one of the corresponding Band Gain
LEDs started to blink. Then, when you pressed the second
[BAND SELECT] button, two more things happened: the
Numerical LED Display changed to show the number “0,” and a
second Band Gain LED started to blink. Each additional [BAND
SELECT] button you press adds a band and a blinking LED to
the Edit Group.
But why did the Numerical LED Display change to a zero?
Because, once you have selected an Edit Group, you can cut or
boost the gain of all of the bands in the Edit Group at once. They
will move up or down together. The zero in the display represents
a “benchmark” for the amount of gain change that happens to the
Edit Group. The 7-segment LEDs can't display the gain values of
each band within the Edit Group all at once, so if you raise the
overall level of the Edit Group by 2 dB, that’s the number you will
see. The function of the display in this case is to tell you the
Relative Gain amount.
For the sake of clarity, when this manual describes what is shown
in the 7-segment LEDs while changing the overall gain value of
the Edit Group, we will refer to it as the Relative Gain display.
Here’s an example: let’s say you have selected the bands at 4k and
5k as your Edit Group. The initial gain value for 4k is +2 dB and
the gain value for 5k is -2 dB. The Relative Gain display at this
point will read “0.” If you rotate the encoder clockwise through
four values, the final value of the Relative Gain display will be a
“2.” The actual gain values for 4k and 5k are now +4 dB and 0 dB,
respectively, which will be indicated by their Band Gain LEDs.
For maximum preservation of
fidelity of the input signal, the
largest number of bands in a
channel should be set to 0 dB.
For example, if you have
more than half of your bands
set to some cut amount and
the majority of those cut
frequencies are at -4 dB, then
select all bands and
compensate by +4 dB.
Proportional Gain Memory
It’s possible you may see numbers as large as 24 in the Relative
Gain display. This is due to a very powerful aspect of the Relative
Gain feature, and it will require some careful explanation.
Here’s another example. Let's say you have two bands selected.
The first band is set to 0 dB, and the second band is set to -12 dB.
The Relative Gain display reads “0.” If you turn the [VALUE]
encoder to the right, you will see that number change from 0 to 12
37
3 Basics of Equalization
upward until it reaches 24. This is because that’s how far the band
that was set to -12 dB had to travel until it hit the “ceiling,” or +
12 dB (see fig. 2).
But what about the band that was set to 0 dB originally...was it
boosted to +24 dB? The answer is, “Yes and no.” It was, in the
sense that the DEQ830 keeps track of the proportional values of
the bands, even if they exceed the +/-12 dB limit of gain change
for a frequency. But the audible audio gain is limited to +/-12 dB.
The reason the DEQ830 keeps track of the gain relationship
between the bands in the Edit Group is simple. It's so you can
change your mind, pull them back down to values within the +/-
12 dB limit, and still have them be the same distance apart!
For example, let’s say you decided these frequencies have been
boosted too much, and you cut them by 12 dB. At this point the
Relative Gain display would read “12,” with the first band’s Gain
LED at +12 dB and the second band’s Gain LED at 0 dB (as in
fig. 1). So far you haven't really reduced the gain of the first band,
because it’s still at +12 dB. You still want to bring it down a bit, so
you take both frequencies down another 3 dB. So now the Relative
Gain display would read “9,” with band one’s Gain value at +9 dB
and band two’s Gain value at -3 dB. And now you can see that the
gain relationship between the two bands was preserved—they’re
still 12 dB apart.
38
Basics of Equalization 3
One important note, though: Proportional Gain Memory is only
temporary. If you run one or more bands “past” the +/-12 dB
limit and then you exit Edit mode for any reason (such as to store
the program), the gain value of those bands will be remembered as
+/-12 dB (whichever was the value that was last reached for those
bands).
The limits of Relative Gain
There will be times when the Relative Gain display will not go all
of the way up or down to a value of 24. This is because the
DEQ830 takes into account the gain setting of all of the bands
when an Edit Group is formed. If the highest gain setting of any
band in the Edit Group is + 6 dB, then from there down to -12 dB
is only 18 dB. So this is the largest number you will see in the
Relative Gain display if you run the relative gain value all the way
down (see fig. 3 and 4).
39
3 Basics of Equalization
Likewise, if the lowest gain setting of any band in this same Edit
Group is -4 dB, then the largest number you will see in the Relative
Gain display going all the way up is 16 (see fig. 5).
So if you run the Relative Gain display up and down repeatedly
with this Edit Group, the display will hit the "ceiling" at 16 and
bottom out at 18.
The Release Edit Group function
Once you have changed the value of the Edit Group, the DEQ830
will react one of two ways to further presses of the [BAND
SELECT] buttons. To decide which option suits your working
method or circumstance, experiment with the setting for the
Release Edit Group function in Utility Mode.
If this function is on, the very next [BAND SELECT] button
you press after you have changed the level of the Edit Group will
“release” all of the previously selected bands. The only band that
will be selected is the one you just pressed. You will know this
happened because only Band Gain LED will now be blinking.
If the Release Edit Group function is set to “Off,” the next
[BAND SELECT] button you press after you have changed the
level of the Edit Group will simply add that band to the Edit
Group.
Remember, if you want to
keep the edited curve or
program, be sure to store it in
memory. For instructions on
how to do this, turn to page
For a more detailed explanation of the Release Edit Group
function, see page 46.
40
Basics of Equalization 3
Basic operation: Store mode
Once you have created a program you would like to save, press the
[STORE] button to enter Store mode. This will cause the
Numerical LED Display to blink with the number of the current
program.
Turning the [VALUE] encoder allows you to choose a program
number between 00-99 as the destination for your edited program.
Once you have chosen the location you want, press the [STORE]
button again or just press the [VALUE] encoder. This will store
the program into the user location you selected.
Remember, if at any time you decide you do not want to save the
edited program, simply press the [PROGRAM] button to return
to Program mode. Your edited program will still be in memory, as
indicated by the flashing LED above the [STORE] button. The
destination program will not have been overwritten.
Basic operation: Save Curve mode
Saving an EQ curve is very similar to storing a program. Once you
have created an EQ curve you would like to save, press the [SAVE
CURVE] button to enter Save Curve mode. This will cause the
Numerical LED Display to blink the number of the curve you’ve
been editing.
As we said earlier, you
should leave Curve 00’s gain
settings at 0 so that you may
use it for building new
curves. This probably will
save you a lot of time and
effort.
Use the [VALUE] encoder to select a curve number between 00-
99 as the destination for the edited curve. Once you have chosen
the location you want, press the [SAVE CURVE] button again or
just press the [VALUE] encoder. This will save the curve’s gain
settings and Channel Level setting into the location you selected.
When you enter Save Curve
mode, Real Time Analyzer
mode is disabled. You will
have to re-enter the Real
Time Analyzer mode after
you exit Save Curve mode.
And if at any time you decide you do not want to save the edited
curve, simply press the [PROGRAM] button to return to
Program mode. Your edited curve will still be in memory, as
indicated by the flashing LED above the [STORE] button. The
destination program will not have been overwritten.
Basic operation: Retrieve Curve mode
One of the quickest ways to create a program is to select curves
from the Curve Bank and copy them one at a time into a channel
or Link Group. To enter Retrieve Curve mode, hold one of the
[CHANNEL SELECT] buttons as you turn the [VALUE]
encoder. The Curve LED will light to indicate that the Numerical
LED Display is now showing curve numbers from the Curve Bank.
Curves will be applied to the
channel once you release the
[CHANNEL SELECT]
button. This allows you to
“audition” the curves
visually before changing the
audio.
As you scroll through the curves you will see the Band Gain LEDs
change to reflect the settings of the curves you are passing over,
but they will not be loaded into the selected channel until you
release the [CHANNEL SELECT] button. This prevents having
to listen to the audio through curves you know you don’t want. As
soon as you release the [CHANNEL SELECT] button, the
channel will assume the EQ and Channel Level settings for the
curve you retrieved.
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3 Basics of Equalization
Copying settings between channels
You can use the Link function while editing to help set up identical
curves on multiple channels. But at some point the curves may
need to diverge slightly (or significantly). Rather than unlinking the
channels and starting all over again, you can use the Curve Bank to
“bounce” the settings from one channel to another. Then you can
begin diversifying the settings of the channels to match the needs
of the incoming audio.
To do this, select the channel from which you wish to copy, and
save it in an unused location in the Curve Bank. Then simply select
the destination channel and retrieve the curve you just stored.
Basic operation: Channel Level mode
To enter Channel Level mode, just press the [CHANNEL
LEVEL] button while you are in Program mode. This allows you
to use the [VALUE] encoder to adjust the level of the currently
selected channel or Link Group.
The DEQ830 will allow each channel to be boosted up to +12 dB
or cut to -12 dB. If you want another 6 dB of gain (for a total of
18 dB), you will find that in the Master Level function in Utility
mode. But remember, the settings for Channel Level mode are
stored with each program. The settings for the Master Level
function are not.
To exit Channel Level mode and return to Program mode, press
the [PROGRAM] button.
Basic operation: Link mode
The ability to link channels is a very handy feature. The most
common application is in setting up matching EQ curves for
stereo instruments or program material, but you may link up to
eight channels together if you wish. The first thing to do is decide
which channels you would like to link, and then pick one of them
to become the “primary” channel. All other channels that you link
to the primary channel are known as “non-primary” channels. As
soon as they are linked, all non-primary channels will adopt the
EQ curve of the primary channel. From that point on, when you
make an edit on the primary channel, an identical edit will be made
to the audio passing through the non-primary channel as well. This
includes changes to the Channel Level setting, also.
To make it happen, hold down the [LINK] button and press the
[CHANNEL SELECT] button of the channel(s) you wish to
link to the primary channel. You will know the channels are linked
when you see more than one channel with a yellow Channel
Number LED lit. You can now make an edit to any linked channel
and it will affect all linked channels. To unlink a channel, hold
[LINK] while pressing the linked channel’s button. Note that the
primary channel cannot be unlinked from its Link Group.
42
Basics of Equalization 3
Remember that a non-primary channel is “mirroring” the settings
of the primary channel. When you perform an edit on a non-
primary channel, you aren’t actually editing that channel; you are
actually changing the primary channe, and the audio for all linked
channels will be affected by the edit. But whatever settings existed
on the non-primary channel before it was linked will still be there
when you unlink it.
To find out which channel is the primary channel in a Link Group,
press and hold the [LINK] button. The Channel Number LED
for the primary channel will flash.
Basic operation: Real Time Analyzer mode
When you enter Save Curve
mode, RTA mode is exited.
When you finish saving the
curve, you have to re-enter
RTA mode manually.
The DEQ830 is capable of a “light show” that is even more useful
than it is entertaining. Real Time Analyzer (RTA) mode uses the
Band Gain LEDs to show you exactly which frequencies are
present in the audio signal that is passing through the DEQ830.
This is an extremely useful tool that has been a mainstay of serious
sound reinforcement engineers for decades.
To enter RTA mode, simply press the [RTA] button located above
the [POWER] button. Immediately, the DEQ830 will start giving
you visual feedback as to what is going on with the instrument or
mix that is being processed. RTA mode can show you the
frequencies present in the signal either before or after the signal is
processed. To select which you want to see, use the [MONITOR
SELECT] button, located above the [BYPASS] buttons, to toggle
between Input and Output. The green LEDs above the button
will indicate what you are seeing.
[BYPASS] and [ALL] work
the same in RTA mode as
they do in Program mode.
When you hit one of these
buttons, the Bypass status of
the channels will change as
described on pages 28 and
If you press a [CHANNEL SELECT] button while in RTA
mode, the unit will remain in RTA mode, and the Band Gain
LEDs will show the audio going through that channel. By
switching channels while in RTA mode, you will get a better
picture of what’s going on with the mix.
If you were in Program mode
when you entered RTA mode,
turning the [VALUE]
encoder will change the
program number and the
DEQ830 will exit RTA mode.
If you were in Edit mode
when you entered RTA mode,
the encoder will edit the
bands you had selected.
To exit Real Time Analyzer mode, simply tap the [RTA] button..
Using the [VALUE] encoder in RTA mode
The response of the [VALUE] encoder is determined by the state
the DEQ830 was in prior to pressing the [RTA] button. It might
help to think of RTA mode as a “submode” for whatever mode
the unit was in before you put it into RTA mode. If you had
selected an Edit Group and then entered RTA mode, the Edit
Group remains active. This is extremely useful, as you can see the
changes you are making to the sound as you turn the encoder! But
if you were in Program mode first, i.e., if you had simply been
scrolling through programs before you pressed the [RTA] button,
then the function of the [VALUE] encoder at that point was, and
remains, program selection. So be careful! Turning the [VALUE]
encoder can cause the DEQ830 to exit RTA mode and select
another program.
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3 Basics of Equalization
Metering modes
The DEQ830 allows you to choose how the Band Gain LEDs will
respond in RTA mode. This is done in Utility mode, where you
can use the [VALUE] encoder to select between the four different
settings of the Peak Mode function, as shown in the chart below.
Held peaks may be reset at
any time by pressing the
[RTA] button and holding it
for about a second.
Displayed
Setting
Name
Description
Peaks are not held.
0
No Hold
1 Second
2 Seconds
Infinite
1
Peaks are held for one second.
Peaks are held for two seconds.
2
Inf
Peaks are held until cleared, or
until you exit RTA mode.
If you want to reset the peaks while they are being held, press and
hold the [RTA] button for about a second.
44
Basics of Equalization 3
Basic operation: Utility mode
To return to Program mode
from Utility mode, press the
[PROGRAM] button.
This is where you will find some of the features that govern the
way the DEQ830 operates in the other modes. They are what you
would call “global” settings, in that their status is not stored with a
program. No matter which program you call up, these settings will
not change.
In Utility mode, the Band
Gain LEDs will spell out an
abbreviated form of the name
of each function, as shown in
the “Displayed” column in
the table on this page.
Press the [UTILITY] button to access Utility mode. Pressing it
repeatedly will cycle through all of the functions that you may edit
in this mode. An alternate selection method is to press and hold
[UTILITY] and turn the [VALUE] encoder in either direction.
The following table shows the functions that are available in Utility
mode:
Function
Displayed
Options
Default
Value
Master Level
M. LVL
+/- 6 dB
Off/On
0 dB
Release Edit Group
Edit Time Out
REL E.G.
EDIT T.O.
MIDI CH
PRG CHG
MIDI O/T
INTCLOCK
INPUT
On
Off/On
Off
ALL
On
MIDI Channel
All, 1-16
Off/On
MIDI Program Chg
MIDI Out/Thru Select
Sample Rate Select
Force Analog Input
Fast Program Select
Peak Mode
Out/Thru
44.1/48
Thru
48
Auto/Analog
Off/On
Auto
On
PRG FAST
PEAK
0, 1, 2, INF
Send?
2
Sys-Ex Transmit
SND SYX
N/A
Note that as you switch from one function to the next, the
Numerical LED Display will change to show the value of the
selected function. In each mode, you can change the value by
turning the [VALUE] encoder. The following pages will describe
what each function does.
Master Level (+/- 6 dB)
The Master Level function is one way to customize the DEQ830
to your environment. If the equipment in your setup tends to send
very hot signals, you can use this function to prevent the output of
the DEQ830 from clipping.
45
3 Basics of Equalization
When a hot line level signal comes in, the DEQ830 has plenty of
headroom to deal with it. But if you perform some radical
equalization on this signal, it is possible that the combination of
the incoming hot signal plus the equalization you have done may
put the signal “over the top” and within clipping range. The
Master Level function allows you to reduce the level of the
equalized signal before it reaches the final output stage of the
DEQ830.
Don’t confuse this with the Channel Level settings in Edit mode.
The Channel Level settings are stored with the program, and
therefore may vary from program to program. The Master Level
setting is global; i.e., it is always active and will affect every
relationship between Channel Level and Master Level.
To lower or raise the Master Level setting, use the [VALUE]
encoder.
For an explanation of how to use the Channel Level control
feature, see page 32.
Release Edit Group (On/Off)
Of all the Utility mode features, this is the one that will most
affect the way you work with the DEQ830. The Release Edit
Group setting determines the behavior of the [BAND SELECT]
buttons in Edit mode.
If you are likely to edit only
one or two bands at a time
when constructing a new
curve, set the Release Edit
Group function to On. This
will enable you to move more
quickly across the audio
spectrum.
For the sake of describing this feature, let’s review some things we
already know. When you press a [BAND SELECT] button, you
enter Edit mode. If you don’t turn the [VALUE] encoder right
away, you can keep pressing [BAND SELECT] buttons until you
have several of them selected simultaneously. This is called
selecting an Edit Group.
Once you have selected an Edit Group, you can cut or boost the
gain of all of the bands in the Edit Group simultaneously; they
will move up or down together. The Release Edit Group feature
does not affect these things; this is always how the DEQ830
operates.
However, once you make an edit, the Release Edit Group feature
comes into play. If it is set to “On,” the very next [BAND
SELECT] button you press will “release” all of the previously
selected bands. The only band that will be selected is the one you
just pressed. You will know this happened, because only that
band’s Gain LED will be blinking.
If the Release Edit Group feature is set to “Off,” the next
[BAND SELECT] button you press after you have changed the
level of the Edit Group will simply add that band to the Edit
Group. The upside of this is the convenience of being able to
boost three frequencies +3 dB, for example, and then add another
frequency to the pile and boost them all another +2 dB without
having to reselect the first three. The downside is that you will
have to deselect all four bands if you want to grab one more
frequency and edit it by itself.
46
Basics of Equalization 3
There are pros and cons to both ways of working. So, experiment
with this feature and see which way works best for you.
To enable or disable the Release Edit Group feature from this
Utility mode page, just turn the [VALUE] encoder.
Edit Time Out (On/Off)
The Edit Time Out function serves as an “auto-exit” feature.
When it is enabled, if you do not change the gain value of any
band or Edit Group for 30 seconds, the DEQ830 will exit
automatically to Program mode.
We have included this feature so the DEQ830 can mold itself as
seamlessly as possible into your working style. If you prefer not to
have the unit continue reminding you it is still in Edit mode by
blinking its LEDs (vying for your attention, as it were, with the VU
meters on your mixer), then Edit Time Out is a feature you will
appreciate.
On the other hand, if you prefer to have the DEQ830 remain in
Edit mode so you will not lose your chosen Edit Group when the
unit returns to Program mode, you may want keep the Edit Time
Out function off.
The default setting for this function is "Off"; to enable it turn the
[VALUE] encoder.
MIDI Channel (ALL, 1-16)
The setting for this function determines which MIDI channel the
DEQ830 will use to send and receive program changes. The ALL
setting means program changes will be received regardless of
which channel they are on. When ALL is selected, program
changes will be sent only on channel 1.
Use the [VALUE] encoder to select the desired setting.
MIDI Program Change (On/Off)
This function determines whether the DEQ830 responds to MIDI
Program Change messages. The default setting for the MIDI
Program Change function is “On.” If you want the DEQ830 not
to respond to program changes, use the [VALUE] encoder to
change it to “Off.”
MIDI Out/Thru Select (Out/Thru)
Sometimes it is necessary to “daisy-chain” MIDI devices so the
MIDI data from one unit will be passed through one or more
other pieces of MIDI gear until it is able to reach the last unit in
the chain. The DEQ830 will allow you to do that; just toggle this
function’s setting from Out to Thru (displayed as “thr”).
The setting on this page will not affect whether or not the
DEQ830 will send its memory out the MIDI Out jack. When that
47
3 Basics of Equalization
command is initiated (Button 11), the sys-ex data will be sent in
either case.
Internal Clock Sample Rate Select (44.1/48)
The DEQ830 automatically senses an incoming digital signal
through its ADAT Optical input and slaves its internal clock to
that, whether the rate is 44.1k or 48k. But if you need the
DEQ830 to serve as an A/D converter, then it will need to be the
master clock for the receiving device.
You may prefer to record the output of the DEQ830 at either
44.1k or 48k. Use the setting of this function to set the internal
clock to the desired sample rate. Once your choice is confirmed,
you’ll see the Sample Rate LEDs change from one rate to the other.
Force Analog Input (Auto/Analog)
There may be times when you want the DEQ830 to ignore an
incoming digital signal. This function gives you an solution that is
easier than reaching around to the back of the rack and
unplugging the cable going into the ADAT Optical input.
Auto is the default value. To force the DEQ830 to listen only to
the balanced inputs, switch this setting from Auto to Analog.
Fast Program Select (On/Off)
This setting controls the behavior of the [VALUE] encoder as
you use it to select programs. When this function is set to its
default value of “On,” the current program will change instantly
when you turn the [VALUE] encoder.
When set to “Off,” turning the encoder will not immediately select
a program. Instead, the display will flash the program numbers as
you scroll through them, but the program won’t actually change
until you press the [VALUE] encoder to confirm the selection.
This prevents accidental program changes.
Peak Mode (0, 1, 2, Inf)
This function allows you to control the behavior of the Band Gain
LEDs while in Real Time Analyzer mode, as described on page 44.
System Exclusive Transmit (Send?)
When on this page, pressing the [VALUE] encoder will cause the
DEQ830 to transmit all of its programs and curves over the MIDI
Out jack in “system exclusive” (sys-ex) format. This is a great way
to back up your settings, and the combination of this function and
the next makes it easy to configure the DEQ830 for particular
applications.
Once the transmission has begun, you will see a brief message of
“Sending,” followed by the message “Done.”
48
Basics of Equalization 3
This process is not affected by the setting of the MIDI Out/Thru
Select function. When you instruct the unit to Transmit, the sys-ex
data will be sent whether the MIDI jack is set to Out or Thru.
Receiving System Exclusive bulk dumps
The DEQ830 is always ready to receive a new bank of programs
and curves into its internal memory. Once an external device
begins sending the proper sys-ex data, the DEQ830 will display
the message “Rcving,” short for “receiving.” When the sys-ex
transmission is complete, the DEQ830 will let you know by
displaying the message “Done.” While the bank is being received,
front panel edits and mode changes will be disabled.
Warning! Sending a sys-ex
bank into the DEQ830 will
overwrite the internal
memory. Make sure you
have backed up internal
memory before you load in
a new set of programs and
curves.
There is one thing you can do during this time, though. If you
change your mind in the middle of the transmission and realize
you’ve loaded in the wrong bank (or worse, you forgot to back up
the programs and curves first), you can interrupt the transmission
by pressing the [PROGRAM] button. The display will show the
word “Aborted” and then return to Program mode. But you’d
better act quickly, as the whole process takes only about 30
seconds.
And unfortunately, as soon the message “Rcving” is displayed the
DEQ830 begins overwriting the Program and Curve Banks. If you
saw that message you will have lost some data. But if you
interrupted the transmission, you will have managed to save some
of the programs and curves.
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3 Basics of Equalization
The "Hidden" Modes
There are a couple of sub-levels of operation that can be accessed
by pressing different buttons. We covered a number of modes on
the preceding pages; here are two more “hidden” modes:
Demonstration mode
Sometimes it’s fun to have a lot of little lights flashing from the
stage or in the studio. The DEQ830 has a special key combination
that will activate a “fireworks display” for the entertainment of
your clients, audience, or children. In this mode the DEQ830
automatically cycles through the first 25 programs at a rate of 1
per second. To begin the pyrotechnics, first make sure you are in
Program mode. Once you are, simultaneously press the
[UTILITY] button and the [CHANNEL SELECT] button for
Channel 6.
To help prevent an accidental exit from Demonstration mode, only
a few controls are active in this mode. The [MONITOR
SELECT], [BYPASS] and [BYPASS ALL] buttons work the
same way they do in Program mode (audio is bypassed by default).
The [CHANNEL SELECT] buttons can be used to switch
channels.
To exit Demonstration mode, press the [PROGRAM] button.
Lock mode
To access Lock mode, first you must turn off the DEQ830. Then
turn the unit back on, wait until you see the letters “DEQ830” in
the display, and then hold down the [UTILITY] button. After a
couple of seconds you will see the word "Lock" appear in large
letters above the [BAND SELECT] buttons. This mode allows
you to do one simple thing—lock the DEQ830’s controls. To do
this, use the [VALUE] encoder to select “On” for the Lock
function. Default is “Off,” of course.
This function enables you to choose a particular program as the
only one that can be selected once the DEQ830 is powered on.
After this has been done, pressing any button besides the
[POWER] button will cause the Numerical LED Display to show
“Lo” for “locked.” This is handy for environments in which the
DEQ830 is used for tuning a room, for example, or whenever you
don't want someone calling up a different program, editing the
current program, and/or storing a different program on top of the
one you have created for a particular application.
Before you try this feature,
make sure you’re happy
with the program you had
selected prior to turning
the unit off. It will be the
program you are “stuck”
with when you turn the unit
back on after enabling the
Lock feature.
It's simple to restore the DEQ830 to full functionality (i.e.,
“unlock” it). Just turn the unit off and power it up in Lock mode
again (turn the unit on and then hold the [UTILITY] button).
Then use the encoder to turn this feature off. The next time you
power up the DEQ830, it will operate normally.
50
Basics of Equalization 3
Equalization Artifacts
When you apply a lot of EQ (6dB or more), you may hear some
consequences on the output. Here are a few common side effects
to applying a lot of equalization and some ways to avoid them.
The potential for artifacts is
highly dependent on the
audio source material. A
DEQ830 curve that works
well for processing one
source may clip when
Distortion
If you boost too many frequencies too high, you will distort the
output. If this happens, the channel’s red CLIP LED will light. To
avoid this, turn down the signal being sent to the DEQ830. Other
options include adjusting the Channel Level settings in Edit mode,
or adjusting the Master Level setting in Utility mode. The best
option is to try another method of achieving the desired effect: cut
the highs instead of boosting the low frequencies; reduce the lows
and highs instead of boosting the midrange, etc.
processing another source,
depending on which
frequencies are present.
Making the curve work may
be simply a matter of a slight
adjustment in the gain setting
for one or two bands.
Noise
If you boost the high frequencies enough you may hear noise in
your system that was inaudible otherwise. If this is objectionable,
you may want to gate that channel when it isn’t being used or
automate the console so that channel is muted when that
instrument isn’t playing.
Instruments usually sound
better when you cut the
problem frequencies instead
of boosting the frequencies
you want to feature.
Phasing
You may hear some phase distortion if you apply a lot of EQ,
such as boosting 12dB on several bands, for example. This is just
the nature of EQ—the more you cut or boost, the more phase
distortion will occur. Try getting the same effect with less EQ; try
cutting instead of boosting; try a different position for the
microphone. All of these suggestions can help you to achieve the
desired effect with minimal phase distortion.
51
3 Basics of Equalization
Constant Q vs. Variable Q
What makes the DEQ830 unique?
Early graphic equalizers relied solely on a form of equalization
known as “Variable Q.” The DEQ830, on the other hand, is what
is known as a “Constant Q” equalizer. This method of
equalization is a relatively recent development in the history of
sound reinforcement and recording technology. As you will see
illustrated in the charts in this section, the Constant Q method
allows for a higher degree of control over the sound being
processed because of its significantly greater accuracy.
Before we go any further, it’s time for some definitions:
Q
The range of frequencies affected by a band
Variable Q
A process in which the range of frequencies
affected by a band changes as the amount of
gain is cut/boosted
Constant Q
A process in which the range of frequencies
affected by a band stays the same as the
amount of gain is cut/boosted
It may help to define these terms visually as well.
In the following illustration, we see the three basic terms that
govern the operation of a single band. The vertical bar of the
graph represents decibels of cut/boost, and the horizontal bar
represents frequency in Hz. The dotted line leading to the center
of the curve indicates the frequency at which this band is set. You
can see that in this example, Q covers a range of frequencies from
about 200 Hz to about 5 KHz.
In the next illustration, the difference between a narrow Q and a
wide Q is seen:
52
Basics of Equalization 3
Variable Q
In the next illustration, the wider and more gradual curve
represents a lower gain setting for a Variable Q equalizer. The
narrower and more steep curve represents a higher gain setting at
the same frequency:
The previous illustration has been exaggerated somewhat to make
the point, but you can see how a lower gain setting also boosts
frequencies that overlap to some extent into the regions affected
by the next highest and lowest frequency band controls.
Constant Q
In contrast, a Constant Q equalizer has a more consistent range of
frequencies under its control throughout its cut/boost range, as
illustrated below:
53
3 Basics of Equalization
Multi-band application and results
So far we have only dealt with cutting or boosting single frequency
bands. The differences between the Constant Q and Variable Q
methods become more “graphic,” if you will, when adjacent
frequency bands are involved.
In this example, three adjacent bands are used. They have settings
of + 6 dB, 0 dB, and + 6 dB, respectively:
You can see how the 0 dB setting on the Variable Q equalizer
merely serves to round off the top of the curve; in actuality, this
translates into a boost in the range of frequencies under that
band's control. You would have to cut the gain on that band
significantly to reduce the unintended consequences of boosting
the other two frequency ranges.
The Constant Q equalizer, on the other hand, has more precise
control over each of the frequency bands. As you can see in this
example, the effect on the center band is significantly lower:
54
Basics of Equalization 3
To further illustrate the differences, here is a pair of examples in
which three adjacent bands have settings of + 3 dB, -3 dB, and + 3
dB, respectively:
Remember that at lower gain settings, there is an even wider Q for
a given frequency band on a Variable Q equalizer. The center
frequency band needs to be edited even more drastically in order
for any noticeable reduction of frequencies in its range.
The corresponding illustration for the Constant Q equalizer speaks
for itself:
We offer this information regarding the differences between
Constant Q and Variable Q equalizers not as an attempt to
persuade the world to reject Variable Q equalizers out of hand; in
some applications either would do the job nicely. But when a
greater degree of control over the program material is needed, a
Constant Q equalizer like the DEQ830 offers a significant
advantage.
55
3 Basics of Equalization
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56
4 Applications
This section is designed to get you started with the DEQ830 by
giving some sample settings. These are merely suggested settings;
experiment and find your own once you begin to hear what the
DEQ830 does to your sound.
In a way, it’s absurd to suggest EQ settings without knowing what
the source sounds like. EQ is a tool that’s used to change the
timbre of a sound, and it’s impossible to suggest an EQ setting
that, for example, will make all guitars sound better. So the goal of
this section is to give you some ideas for using EQ on your own
tracks.
General EQ tips
Rock Kick Drum
A rock and roll kick drum is usually EQ’d quite a bit to make it
sound the way it does on the radio. Usually an engineer will choose
to cut some of the woofy low-midrange, while boosting the high-
end "slap" and maybe even some of the lows. Here is a setting to
try on a close-miked kick drum:
•
•
•
Select all frequencies below 80Hz and boost 3dB
Cut 500Hz by 8dB
Boost all frequencies above 5kHz by 4dB
You may also want to apply some compression and gating with the
Alesis CLX-440.
Vocal Air
A popular effect on vocals is to boost the high frequencies to add
"air" to the vocal. This is an especially popular effect on ballads
sung by R&B divas. This effect is achieved by boosting the high
frequencies:
•
•
Boost 16 kHz by 6dB
Boost 20 kHz by 6dB
Tape Hiss Removal
If a recording has a lot of tape hiss, such as one transferred from
cassette, you can usually get rid of it by dropping the high
frequencies a bit:
•
Select all frequencies from 8kHz up and cut them by 6dB
Adjust the gain of different bands to compromise between
keeping the high end of the recording and eliminating tape hiss.
57
4 Applications
Eliminating Feedback
During a live performance, you may experience feedback if a
microphone is placed too close to a monitor. However, this
feedback often occurs at one frequency before it happens at
others. You can "ring out" the monitor by using EQ to cut the
frequency that’s feeding back. The following is best to try when the
band and audience are not present:
This procedure can be an
effective tool in isolating and
eliminating feedback in the
main or house system as well.
1. Insert the EQ between the mixer’s monitor output and the
monitor amplifier.
2. Slowly and carefully raise the monitor level to the point of
feedback. Notice that it always feeds back at the same
frequency unless the mic is moved a lot. As soon as you hear
feedback, turn the monitor level down, but not off.
3. Select a band that is near where you think the feedback is
occurring. For example, if you’re getting high-frequency
feedback, try 6.3 kHz.
4. Slowly raise the 6.3 kHz Band Gain level while listening for
feedback. If you hear feedback, cut that frequency because you
guessed right.
5. If you don’t hear feedback, return that band to “0” and repeat
this procedure with another frequency band. Once you hear
feedback, cut that frequency.
If you don’t hear feedback at any frequency using this method, try
boosting the monitor level a little more.
Filtering effects
The answering machine
A popular vocal effect is to filter the voice to a limited frequency
range. This “telephone” effect can be used on any instrument or
mix. Here’s how to get that sound on the DEQ830:
1. Press all of the [BAND SELECT] buttons in the ranges
from 25 Hz to 630 Hz and from 6.3 kHz to 20 kHz on the
channel you are using. Or you can hold down a [BAND
SELECT] button and turn the [VALUE] encoder to select
these frequency ranges.
2. Use the [VALUE] encoder to reduce all of these frequencies
until their LEDs are at -12 dB.
3. Select all of the unedited frequencies and boost them as high
as you can without clipping the signal.
4. Be sure to toggle the [BYPASS] button to compare the result
with the original.
58
Applications 4
Comb filtering
You'll understand how this effect process got its name once you
see the way it looks when recreated on the DEQ830. This one
works especially well with two channels that carry the left and right
signals from a stereo audio source:
Note: depending on the
incoming audio, it may be
necessary to reduce the gain
on some bands to prevent
clipping.
1. Starting from the far left of the band spectrum, press every
other [BAND SELECT] button and take those bands all the
way down to -12 dB. Then select the unedited bands and boost
them +6 dB. When you’re done, look at the LEDs on the
DEQ830 and remember the “comb” analogy. The bands set to
+6 dB are the “teeth” of the comb, and those set to –12 dB
are the spaces between the teeth.
There are preset curves similar
to the ones used in these
examples. You may find it
interesting to compare the way
various audio sources are
affected by somewhat similar
curves.
2. For an even more interesting effect, unlink the first channel
from the channel carrying the other side of the stereo
spectrum and create the exact opposite settings. In other
words, take the “odd” bands on the second channel to +6 dB
this time and the “even” bands to –12 dB. Be sure to toggle
the [BYPASS] and [LINK] status of each channel to get an
idea of what is being done to the signal as it passes through
the DEQ830.
3. Experiment with different sized "teeth" and "spaces." Put two
adjacent frequencies down and the next one up, repeating the
pattern. Try "broken" teeth (i.e., boosting some frequencies
more than others)! Adjust which frequencies to emphasize/de-
emphasize to suit the incoming audio.
Settings chart
We've provided the chart on the next page because we know some
of you prefer to have a hard copy of your favorite settings. And
thanks to the digital heart of the DEQ830, you'll always be able to
reconstruct the curve exactly as it was using the numbers you write
down.
A few notes about filling out the chart:
1. When a value is exact, like +8 or –4, place a dot in the
appropriate square above the band.
2. When the band’s value is zero, or flat, draw a dash through that
square instead of a dot. This will help you keep track of
numbers above and below zero by giving you a visual
reference point (just as the green LED does on the front
panel). You’ll naturally begin to draw an extended line through
consecutive bands when they’re all set to zero.
3. For intermediate values like +3.5, we suggest writing that
number in the square above that band which most closely
approximates the actual value.
4. Don’t forget to record the Channel Level setting!
59
4 Applications
60
5 Troubleshooting
Line Conditioners and Protectors
Although the DEQ830 is designed to tolerate typical voltage
variations, in today’s world the voltage coming from the AC line
may contain spikes or transients. These can cause audible noises,
and they can stress your gear and, over time, possibly cause a
failure. There are two main ways to protect against this, listed in
ascending order of cost and complexity:
•
Line spike/surge protectors. Relatively inexpensive, these
are designed to protect against strong surges and spikes, acting
somewhat like fuses in that they need to be replaced if they’ve
been hit by an extremely strong spike.
•
Line filters. These generally combine spike/surge protection
with filters that remove some line noise (dimmer hash,
transients from other appliances, etc.). A good example is the
Isobar™ series from Tripp Lite.
Care and Maintenance
Do not spray cleaning
solution of any sort onto the
front panel of the DEQ830.
If a cleaning becomes
necessary, spray a
recommended cleaning
solution onto a cloth first,
and use the cloth to clean
the front panel.
Cleaning
Disconnect the AC power supply, then use a damp cloth to clean
the DEQ830’s metal and plastic surfaces. For heavy dirt, use a
non-abrasive household cleaner such as Formula 409™ or
Fantastik™. DO NOT SPRAY THE CLEANER DIRECTLY
ONTO THE FRONT OF THE UNIT AS IT MAY DESTROY
THE LUBRICANTS USED IN THE SWITCHES AND
CONTROLS! Spray onto a cloth, and then use the cloth to clean
the unit.
61
5 Troubleshooting
Troubleshooting Index
Symptoms
Cause
Solution
Test with a known good
input.
No audio at outputs.
Weak output signal.
Clip LED lights often.
No input audio.
Bad cables.
Destination is turned
down.
Replace the cables.
Check the connections
and the level of the mixer
or amp to which the
DEQ830 is connected.
Increase level from source
into DEQ830.
Boost channel levels of
quiet program.
Boost Master Level in
Utility mode.
Input level weak.
Output level weak.
(Decide which is the case
by pressing the Bypass
button.)
Input level too high.
Reduce input level at
source.
Output level too high.
Reduce gain of problem
bands within program.
(Decide which is the case
by pressing the Bypass
button.)
Reduce channel levels of
that program.
Reduce Master Level in
Utility mode.
Can’t select new program,
display keeps blinking.
Program Fast is set to
“Off.”
Press encoder to confirm
program selection, or
change Program Fast
setting in Utility mode.
Refer to page 48.
Can’t edit program, can’t
select new program.
Numerical LED Display
keeps flashing “Lo.”
DEQ830 is locked.
DEQ830 is locked.
Unlock DEQ830 in Lock
mode. Refer to page 50.
Unlock DEQ830 in Lock
mode. Refer to page 50.
Must de-select all bands in
order to edit a single band.
Release Edit Group
function set to Off.
Set Release Edit Group
function to On in Utility
mode.
Analog input is ignored
Digital input is ignored
Digital signal present at
ADAT Optical Input.
Change Force Analog
Input setting in Utility
mode.
Force Analog Input is set
to Analog in Utility mode.
Ditto.
62
Troubleshooting 5
Refer All Servicing to Alesis
We believe that the DEQ830 is one of the best signal processors
that can be made using current technology, and should provide
years of trouble-free use. However, should problems occur, DO
NOT attempt to service the unit yourself unless you have training
and experience. Service on this product should be performed only
by qualified technicians. NO USER-SERVICEABLE PARTS
INSIDE.
Obtaining Repair Service
Before contacting Alesis, check over all your cable connections,
and make sure you’ve read the manual.
Customers in the USA and Canada:
If the problem persists, contact Alesis and request the Technical
Support department. Make sure you have the unit’s serial number
with you. Talk the problem over with one of our technicians; if
necessary, you will be given a return authorization (RA) number
and instructions on how to return the unit. All units must be
shipped prepaid and COD shipments will not be accepted.
For prompt service, indicate the RA number on the shipping label.
Units without an RA will not be accepted. If you do not have the
original packing, ship the unit in a sturdy carton, with shock-
absorbing materials such as Styrofoam pellets (the kind without
CFCs, please) or "bubble-pack" surrounding the unit. Shipping
damage caused by inadequate packing is not covered by the Alesis
warranty.
Tape a note to the top of the unit describing the problem,
including your name and a phone number where Alesis can
contact you if necessary, as well as instructions on where you want
the product returned. Alesis will pay for standard one-way
shipping back to you on any repair covered under the terms of this
warranty. Next day service is available for a surcharge. Field repairs
are not authorized during the warranty period, and repair attempts
by unqualified personnel may invalidate the warranty.
Customers outside the USA and Canada:
Contact your local Alesis distributor for any warranty assistance.
The Alesis Limited Warranty applies only to products sold to users
in the USA and Canada. Customers outside of the USA and
Canada are not covered by this Limited Warranty and may or may
not be covered by an independent distributor warranty in the
country of sale. Do not return products to the factory unless you
have been given specific instructions to do so.
Internet Address:
Important information and advice is available on our Web site:
63
5 Troubleshooting
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64
Specifications
Rear Panel I/O (switchable)
Analog:
All measurements done over
a 22 Hz - 22 kHz range with 1
kHz sine wave at -1dBFS
input. Impedances are
Input Connectors:
Output Connectors:
8 balanced 1/4” TRS jacks
8 balanced 1/4” TRS jacks
Digital:
Input Connector:
Output Connector:
measured at 1 kHz.
1 ADAT Optical
1 ADAT Optical
Switch set to +4:
Nominal input level:
Maximum input level:
+4dBu (-15dBFS)
+19dBu (6.9 Vrms)
Nominal Output Level:
Maximum Output Level:
+4dBu (-15dBFS)
+19dBu (6.9 Vrms)
Switch set to –10:
Nominal input level:
Maximum input level:
-10dBV (-16dBFS)
+6dBV (2.0 Vrms)
Nominal Output Level:
Maximum Output Level:
-10dBV (-16dBFS)
+6dBV (2.0 Vrms)
Input impedance:
Output Impedance:
10kΩ
220Ω
MIDI:
MIDI Input:
MIDI Output:
1 5-pin female DIN
1 5-pin female DIN
Audio Performance
Signal To Noise Ratio:
THD+N:
>100dB A-Weighted, Analog In
to Analog Out
<0.005%, Analog In to Analog
Out
Frequency Response:
Power Consumption:
22-22kHz ± 0.50dB, Analog In
to Analog Out
15 Watts Max (100-240 VAC /
50-60 Hz)
Mechanical
Size:
Rack Spaces:
Weight:
1.75" H x 19.0" W x 5" D
1 Space
3.0 lbs. (1.4 kg)
65
Specifications
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66
Warranty / Contact
Alesis LimitedWarranty
ALESIS CORPORATION ("ALESIS") warrants this product to be free of defects
in material and workmanship for a period of one (1) year for parts and for a period of
one (1) year for labor from the date of original retail purchase. This warranty is
enforceable only by the original retail purchaser and cannot be transferred or assigned.
For the most effective service, the purchaser should register the purchase on the
During the warranty period ALESIS shall, at its sole and absolute option, either repair
or replace free of charge any product that proves to be defective on inspection by
ALESIS or its authorized service representative. In all cases disputes concerning this
warranty shall be resolved as prescribed by law.
To obtain warranty service, the purchaser must first call or write ALESIS at the
address and telephone number available on the Alesis Website to obtain a Return
Authorization Number and instructions concerning where to return the unit for
service. All inquiries must be accompanied by a description of the problem. All
authorized returns must be sent to ALESIS or an authorized ALESIS repair facility
postage prepaid, insured and properly packaged. Proof of purchase must be
presented in the form of a bill of sale, canceled check or some other positive proof
that the product is within the warranty period. ALESIS reserves the right to update
any unit returned for repair. ALESIS reserves the right to change or improve design
of the product at any time without prior notice.
For more effective
service and product
update notices, please
register your DEQ830
online at:
This warranty does not cover claims for damage due to abuse, neglect, alteration or
attempted repair by unauthorized personnel, and is limited to failures arising during
normal use that are due to defects in material or workmanship in the product.
THE ABOVE WARRANTIES ARE IN LIEU OF ANY OTHER
WARRANTIES OR REPRESENTATIONS WHETHER EXPRESS OR
IMPLIED OR OTHERWISE, WITH RESPECT TO THE PRODUCT, AND
SPECIFICALLY EXCLUDE ANY IMPLIED WARRANTIES OF FITNESS
FOR A PARTICULAR PURPOSE OR MERCHANTABILITY OR OTHER
IMPLIED WARRANTIES. Some states do not allow limitations on how long an
implied warranty lasts, so the above limitation may not apply to you.
IN NO EVENT WILL ALESIS BE LIABLE FOR INCIDENTAL,
CONSEQUENTIAL, INDIRECT OR OTHER DAMAGES RESULTING
FROM THE BREACH OF ANY EXPRESS OR IMPLIED WARRANTY,
INCLUDING, AMONG OTHER THINGS, DAMAGE TO PROPERTY,
DAMAGE BASED ON INCONVENIENCE OR ON LOSS OF USE OF THE
PRODUCT, AND, TO THE EXTENT PERMITTED BY LAW, DAMAGES
FOR PERSONAL INJURY. Some states do not allow the exclusion or limitation of
incidental or consequential damages, so the above limitation or exclusion may not
apply to you.
THIS CONTRACT SHALL BE GOVERNED BY THE INTERNAL LAWS OF
THE STATE OF CALIFORNIA WITHOUT REFERENCE TO CONFLICTS
OF LAWS. This warranty gives you specific legal rights, and you may also have other
rights required by law which vary from state to state.
This warranty only applies to products sold to purchasers in the United States of
America or Canada. The terms of this warranty and any obligations of Alesis under
this warranty shall apply only within the country of sale. Without limiting the
foregoing, repairs under this warranty shall be made only by a duly authorized Alesis
service representative in the country of sale. For warranty information in all other
countries please refer to your local distributor.
67
Warranty/Contact
Alesis Contact Information
Alesis Distribution, LLC
Los Angeles, CA USA
E-mail:
Website:
Alesis DEQ830 Reference Manual
Revision A by Randy Lee, Taiho Yamada and Edwin Erdmann
Revision B by Bret Victor
Copyright 2003, Alesis Distribution, LLC. All rights reserved
Reproduction in whole or in part is prohibited. Specifications
subject to change without notice.
7-51-0138-C
05/09/2003
68
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