Alesis PEQ-450 User manual

PEQ-450 Reference Manual 1
Five-Band Parametric Equalizer
Reference
Manual
2001

PEQ-450 Manual
2 PEQ-450 Reference Manual

PEQ-450 Manual
PEQ-450 Reference Manual 3
Contents
Welcome!........................................................................................................................6
How to Use This Manual ...........................................................................7
Important Safety Instructions....................................................................8
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 some filtering.................................................................17
Connections.................................................................................................................19
Unpacking and Inspection.......................................................................19
Installing in a Rack ....................................................................................19
Power ...........................................................................................................20
Connecting inputs and outputs ..............................................................22
Connecting to the Channel Inserts of a mixing console: ...........22
Connecting to the Main Inserts of a mixing console: .................23
Connecting to the inserts on an instrument amplifier:..............24
Connecting to equipment with XLR inputs and outputs:.........25
Dual Channel Operation ..........................................................................25
About Audio Cables..................................................................................26
Basics of Equalization............................................................................................... 7
What is equalization?................................................................................27
Description of Controls ............................................................................28
Gain...................................................................................................28
Frequency.........................................................................................28
Q ........................................................................................................29
HPF ...................................................................................................30
LPF ....................................................................................................30
Input..................................................................................................31
Output ..............................................................................................31
Equalization Artifiacts..............................................................................32
Distortion .........................................................................................32
Noise .................................................................................................32
Phasing .............................................................................................32

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Applications.................................................................................................................33
Rock Kick Drum .............................................................................33
Vocal Air ..........................................................................................33
Hum Removal.................................................................................34
Tape hiss removal...........................................................................34
Eliminating feedback .....................................................................34
Troubleshooting.........................................................................................................37
Troubleshooting Index .............................................................................37
Avoiding ground loop noise ........................................................38
Line Conditioners and Protectors ...............................................39
Care and Maintenance..............................................................................40
Cleaning ...........................................................................................40
Refer All Servicing to Alesis.........................................................40
Obtaining Repair Service ..............................................................40
Specifications..............................................................................................42
Alesis Limited Warranty...........................................................................................43

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Welcome!
Thank you for making the Alesis PEQ-450™ a part of your studio.
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 have achieved with them.
One of Alesis' goals is to make high-quality studio equipment
available to everyone, and this Reference Manual is an important
part of that. After all, there's no point in making equipment with all
kinds of capabilities if no one explains how to use them. 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 Studio Electronics

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PEQ-450 Reference Manual 7
How to Use This Manual
This manual is divided into the following sections describing the
various functions and applications for the PEQ-450. While it's a
good idea to read through the entire manual once carefully, those
having general knowledge about studio equipment should use the
table of contents to look up specific functions.
Chapter 1: Quick Start. If you're already familiar with recording,
this will get you started using the PEQ-450 right away. It's a short
guide to the essential elements of connections and operation.
Chapter 2: Connections. This section gives detailed instructions for
connecting the PEQ-450 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
PEQ-450 with a variety of audio sources.
Chapter 5: Troubleshooting. Refer to this chapter if you experience
any problems while using the PEQ-450.
Helpful tips and advice are highlighted in a shaded box like this.
The names of specific controls or connectors on the PEQ-450 are
printed in a special font, i.e., the BYPASS button.
✪When something important appears in the manual, an icon
(like the one on the left) will appear in the left margin. This
symbol indicates that this information is vital when operating
the PEQ-450.

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Important Safety Instructions
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

PEQ-450 Manual
PEQ-450 Reference Manual 9
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.
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, softdrink 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.

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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.

PEQ-450 Manual
PEQ-450 Reference Manual 11
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.
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.
Beim Benutzen dieses Produktes beachten Sie bitte
die folgenden Sicherheitshinweise: (German)
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.

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12 PEQ-450 Reference Manual
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. Verlegen Sie das Netzkabel des Gerätes niemals so, daß man
darüber stolpern kann oder daß es gequetscht wird.
10. Benutzen Sie nur das vom Hersteller empfohlene Zubehör.
11. 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.
12. Ziehen Sie während eines Gewitters oder wenn Sie das Gerät
über einen längeren Zeitraum nicht benutzen den Netzstecher
aus der Steckdose.
13. 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.
14. Dieses Gerät produziert auch im normalen Betrieb Wärme.
Achten Sie deshalb auf ausreichende Lüftung mit mindestens 15
cm Abstand von anderen Geräten.
15. 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.

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PEQ-450 Reference Manual 13
CE Declaration of Conformity
See the Internet site:
www.alesis.com

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Instructions to the User (FCC Notice)
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 and correct the
interference by one or more of the following measures:
2. Reorient or relocate the receiving antenna.
3. Increase the separation between the equipment and receiver.
4. Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.
5. Consult the dealer or an experienced radio/TV technician for help.
This equipment has been verified to comply with the limits for a
class B computing device, pursuant to FCC Rules. In order to
maintain compliance with FCC regulations, shielded cables must be
used with this equipment. Operation with non-approved equipment
or unshielded cables is likely to result in interference to radio and TV
reception. The user is cautioned that changes and modifications
made to the equipment without the approval of manufacturer could
void the user’s authority to operate this equipment.

Chapter 1
PEQ-450 Reference Manual 15
Quick Start Guide
If you can't wait to get started:
The Alesis PEQ-450™ is a unique product, but its basic hookup and
operation is 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 PEQ-450 right away. If
you have questions about any of the features, don’t worry – later
chapters will unveil the mysteries of the PEQ-450's special features.
✪If you're new to signal processing, start with the more detailed
instructions for hookup and operation starting in the next
chapter.
Step 1: Hook it up to a mixer
1. Pull the PEQ-450 out of the package.
2. Plug the POWER jack on the back of the PEQ-450 into a grounded
AC power source with the supplied power cable. Since the PEQ-
450’s power turns on automatically, press the POWER switch to
turn it off during connections.
3. Using a pair of insert cables, plug the insert sends of the mixer to
the CHAN A INPUTS on the back of the PEQ-450.
4. Connect the insert cable return plugs to the CHAN A OUTPUTS of
the PEQ-450.
5. Press the POWER switch on the front of the PEQ-450 to power up
the unit.
For more information on connecting the PEQ-450, see chapter :
Connections.

quick start guide • chapter 1
16 PEQ-450 Reference Manual
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 part that doesn’t change much,
so that you can take your time experimenting with the different
features.
1. Turn the INPUT all the way down so that you don’t distort the
unit.
2. Begin playing your source material. Turn the INPUT knob
clockwise until the average level is around –15 on the INPUT
meter.
3. Turn the BAND 5 Q knob until it reads HIGH SHELF. Adjust the
BAND 5 FREQUENCY and BAND 5 GAIN knobs to hear the effects of
the EQ.
4. Press the BYPASS button to hear your signal without the
equalization effect. Press it again to return to the EQed signal.
Experiment with the other band controls to get acquainted with the
unit.

chapter 1 • quick start guide
PEQ-450 Reference Manual 17
Step 3: Try some filtering
Find a "peaky" signal
A popular vocal effect is to filter the voice to a small frequency band.
This "telephone" effect is also called "futzing" and can be used on any
instrument or mix. Here’s how to get that sound on the PEQ-450:
1. Begin playing your source material. Turn the INPUT knob
clockwise until the average level is around –15 on the INPUT
meter.
2. Press the LPF and HPF buttons on the channel you are using.
3. Set the BAND 5 FREQ knob around 6kHz. Set the BAND 1 FREQ
knob around 800Hz.
4. Have the vocalist sing "yeah yeah yeah yeah yeah".
Note that the band 1 and 5 GAIN and Qknobs do not function when
the HPF or LPF buttons (respectively) are pressed.

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18 PEQ-450 Reference Manual
Front Panel Diagram
4.5k
4.5k4.5k4.5k4.5k4.5k
4.5k
4.5k4.5k
4.5k 150
150
150150
150
150
150
150
150
150
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
2.0
0.25 16
8.0
4.0
1.0
0.5
Rear Panel Diagram

Chapter
PEQ-450 Reference Manual 19
Connections
Unpacking and Inspection
Your PEQ-450 was packed carefully at the factory. The shipping
carton was designed to protect the unit during shipping. Please
retain this container in the highly unlikely event that you need to
return the PEQ-450 for servicing.
The shipping carton should contain the following items:
• PEQ-450 with the same serial number as shown on shipping
carton
• Power Cable
• This instruction manual
Installing in a Rack
The PEQ-450 may be simply set on a table, or installed in a standard
19" audio equipment rack. The rack ears are integral to the unit.
Thermal Considerations in Rack Mounting
The PEQ-450 can be mounted in an equipment rack (taking up 3 rack
spaces) or placed on a table or shelf. When you install it, keep in
mind that heat is the major enemy of electronic equipment. Please
observe the following:
• The PEQ-450 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 PEQ-450 will meet its
published specs or remain reliable if operated outside of these
ranges.
• Always allow adequate ventilation behind the PEQ-450. Do not
seal any enclosure that holds the PEQ-450. It is not necessary to
leave an empty rack space above or below the PEQ-450 unless it
runs hot enough to affect equipment above or below it. If your
environment is unusually warm and not air conditioned, space
between units will help the units run cooler.

connections • chapter 2
20 PEQ-450 Reference Manual
Power
Make sure you read the initial Important Safety Instructions
chapter at the front of this manual.
AC Power Hookup
Plug the female end of the power cord into the PEQ-450’s POWER
INPUT socket and the male (plug) end into a good quality, noise-free
AC power source of the proper rating.
Tip: It’s good practice to not turn on the PEQ-450 until all other
audio cables are hooked up as well. Make sure your amplifier
or powered speakers are switched off when turning the PEQ-
450 on or off to avoid damage.
The PEQ-450 works with any standard line voltage from 100 to 230
volts and comes with a detachable AC line cord suitable for the
destination to which the unit is shipped.
AC Grounding
The line cable is an IEC-spec AC power cable designed to be
connected to a grounded 3-pin outlet, with the third, round pin
connected to ground. Do not substitute any other type of AC cord;
IEC-spec cables of various lengths may be purchased from
electronics stores or your Alesis dealer.
The ground connection is an important safety feature designed to
keep the chassis of electronic devices such as the PEQ-450 at ground
potential. Unfortunately, the presence of a third pin does not always
indicate that an outlet is properly grounded. You may use an AC line
tester to determine this. If the outlet is not grounded, consult with a
licensed electrician. When AC currents are suspected of being highly
unstable in VAC and Hz, a professional power conditioner should be
used.