Alesis DEQ224 User manual

Reference Manual

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Table Of Contents
1
Introduction ..................................................................3
Welcome!......................................................................................................3
DEQ224 Key Features .................................................................... 4
How to Use This Manual................................................................ 5
Important Safety Instructions..................................7
Important Safety Instructions (English)................................... 7
Safety symbols used in this product.........................................................7
Please follow these precautions when using this product: ...................7
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
Sicherheit Symbole verwendet in diesem Produkt.................................11
Folgen Sie bitte diesen Vorkehrungen, wenn dieses
Produkt verwendet wird: ...........................................................................11
CE Declaration Of Conformity..................................................... 13
FCC Compliance Statement ......................................................... 13
Chapter One: Quick Start Guide ..............................15
If you can't wait to get started..................................................................15
Step 1: Hook it up to a mixer ........................................................ 15
Step 2: Try some equalization ...................................................... 16
Step 3: Try a filtering effect.......................................................... 16
Step 4: Store the Program............................................................. 17
Chapter Two: Connections ........................................19
Unpacking and Inspection............................................................ 19
Installing in a Rack ........................................................................ 19
Thermal Considerations in Rack Mounting ............................. 19
AC Power Hookup........................................................................... 20
To use the DEQ224 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
About Audio Cables ........................................................................ 24
Chapter Three: Basics of Equalization...................25
What is equalization? ..................................................................... 25
Description of the Controls .......................................................... 26
Description of the Basic Modes ................................................... 27
Basic operation: Program mode .................................................. 29
Basic operation: Edit mode........................................................... 30
Basic operation: Store mode......................................................... 36
Channel Copy..............................................................................................37

Table Of Contents
2
Basic operation: Channel Level mode........................................ 38
The "Hidden" Modes........................................................................ 39
Button combinations.................................................................................. 42
Equalization Artifacts.................................................................... 43
Constant Q vs. Variable Q ............................................................. 44
Chapter Four: Applications.......................................49
Chapter Five: Program Charts .................................51
Chapter Six: Troubleshooting...................................59
Restoring the Factory Programs & Defaults............................ 59
Line Conditioners and Protectors .............................................. 59
Care and Maintenance................................................................... 59
Troubleshooting Index ..............................................................................60
Specifications................................................................63
Audio Input .................................................................................................63
Audio Output .............................................................................................. 63
Audio Performance ....................................................................................63
Mechanical: ..................................................................................................63
Warranty/Contact Alesis ............................................65
Alesis Limited Warranty.............................................................................65
Alesis Contact Information.......................................................................66

Introduction
3
Welcome!
Thank you for purchasing the Alesis DEQ224™. 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.
One of Alesis' goals 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 DEQ224’s features in a
way that is easy to understand and remember. But even beyond
explaining each feature and parameter, this manual can be the key
that unlocks an application for the DEQ224 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
F
or more effective
s
ervice and product
update notices, please
r
egister your DEQ224
o
nline at:
h
ttp://www.alesis.com/
s
upport/warranty.htm

Introduction
4
DEQ224 Key Features
1. Designed to offer the best of digital technology and analog-
style control: the immediacy of a graphic display with
instantaneous editing of any band or combination of bands, as
well as the ability to store your own programs
2. 60 programs total: 30 preset and 30 user-programmable
3. 48 KHz sampling rate
4. 24-bit A/D and D/A with 28-bit internal processing
5. Two channels of equalization
6. 24 EQ bands per channel, spanning 25 Hz-19 kHz
7. +/- 12 dB boost/cut with center detent
8. Constant Q technology allows finer control between bands
than conventional graphic equalizers
9. LOCK function allows the DEQ224 to be used in "set and
forget" situations, such as control room tuning, main live
mixes, monitor mixes, etc., without fear of accidental
reprogramming
10. Individual Channel Level adjustment per program
11. Master Level adjustment
12. [CHANNEL] button for switching quickly between
Channels A and B, for editing and viewing of EQ curves
13. LINK mode, accessed by [CHANNEL] button, allowing
quick creation of matched EQ curves
14. [BYPASS] button
15. Configurable editing mode to suit the way you work
16. Several methods of accelerated program selection
17. Ability to copy settings from Channel A to Channel B during
Store procedure
18. Instant reset of parameter/gain values with a simultaneous
press of the [DOWN/UP] buttons
19. Easy-to-read 7-segment Numeric LED Display
20. Over 300 Band Gain LEDs, making it easy to read EQ curves
from a distance
21. SIGNAL and CLIP LEDs
22. Balanced input/impedance-balanced output (TRS)
23. Compact 1/2-rack profile
For full operating specifications, see page 63.

Introduction
5
How to Use This Manual
This manual is divided into the following sections describing the
various functions of and applications for the DEQ224. 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.
Chapter 1: Quick Start Guide. If you're already familiar with
equalization, this will get you started using the DEQ224 right away.
It's a short guide to the essential elements of hooking it up and
using it for the first time.
Chapter 2: Connections. This section gives detailed instructions for
connecting the DEQ224 to a variety of typical audio systems.
Chapter 3: Basics of Equalization. This section explains 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
DEQ224 in a variety of settings.
Chapter 5: Program Charts. Here you will find the names for all 60
Factory Programs, with a brief description of each and a small
graphic representation of the front panel settings.
Chapter 6: Troubleshooting. Near the end of the manual you will find
troubleshooting tips and a complete list of the DEQ224’s
specifications.
H
elpful tips and advice are
highlighted in a shaded box
like this.
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 DEQ224.
The names of specific buttons
on the DEQ224 are printed in
a bold font and bracketed:
i.e., the [BYPASS] button.

Introduction
6
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Important Safety
Instructions
7
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

Important Safety Instructions
8
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.