SM Pro Audio CQ15, CQ31 Operating Manual

SM PRO AUDIO CQ15/CQ31

CQ15/CQ31

Graphic EQualizer + compressor

Version 1.0

SAFETY INSTRUCTIONS

CAUTION: To reduce the risk of electrical shock, do not remove the
cover or rear panel of this unit. No user serviceable parts inside. Refer
servicing to qualified personnel only.

WARNING: To reduce the risk of fire or electrical shock, do not expose
this equipment to rain or moisture.

All safety and operation instructions of this manual should be read and adhered
to before operating this equipment.

Retain Instructions: Please retain all safety and operating instructions for future reference.
Follow Instructions: All operation and user instructions should be followed.

Water, Liquid, and Moisture: The equipment should not be used near water, rain, or other

liquids. Make sure that no liquid can leak, spill, or otherwise seep into the equipment.
Ventilation: Please place the equipment so that no obstacles interfere with or impede the

flow of air through the ventilation openings.
Heat:The equipment should be situated away from heat sources such as heaters,

radiators, ovens, and other appliances that produce heat.
Power Source:Make sure your equipment is set to the correct voltage for the country in

which it will be used.
Grounding and Polarization:Precautions should be taken so that the equipment’s

electrical grounding or polarization is not defeated.

SM PRO AUDIO CQ15/CQ31

Power Cord Protection:Power supply cords should be routed so that they are not likely to
be walked on, pinched, damaged, worn, or rubbed by any other device or obstacle.

Cleaning:The equipment should be cleaned only with a light soft cloth. Do not use harsh or
corrosive products on the unit.

Periods of Inactivity:The power cord of the appliance should be unplugged from the outlet
when left unused for a long period of time.

Damage Requiring Service:The equipment should be serviced by qualified service
personnel when:

• The power supply cord or plug has been damaged; or

• Objects have fallen onto, or liquid spilled into the equipment; or

• The equipment has been exposed to rain; or

• The equipment does not appear to operate normally or exhibits a marked change in
performance; or

• The equipment has been dropped, or the enclosure damaged.

Servicing:

The user should not attempt to service the equipment beyond what is described in the
Operating Instructions.

All other servicing should be referred to qualified service personnel.

SM PRO AUDIO CQ15/CQ31

FOREWORD

Dear Customer,
Thank you very much for expressing your confidence in SM Pro Audio products
by purchasing this unit. The CQ15/CQ31 was designed to be a comprehensive
audio processor for home, project and professional studios, live sound
rental companies, repair centers, schools and fixed installations—in short,
virtually any and all venues where audio products are used. Drawing on years
of hands-on experience in the audio industry and valuable suggestions from our
customers, our engineers have developed a product that we are certain will
more then meet your expectations. As with all SM Pro Audio equipment, the
CQ15/CQ31 was designed to provide you with a superb performance, excellent
technical specifications and uncompromising audio quality at an extremely
affordable price.

Regards,
SM Pro Audio

IMPORTANT:

High output volumes may damage your ears,
your monitors, and/or your headphones. Turn down the
LEVEL controls before you switch on the

INSTALLATION

Your SM Pro Audio CQ15/CQ31 was carefully packed in the factory and the
packaging was designed to protect the unit from rough handling. Nevertheless,
we recommend that you carefully examine the packaging and its contents for
any signs of physical damage, which may have occurred in transit.

If the unit is damaged, please do not return it to us, but notify your dealer and
the shipping company immediately, otherwise claims for damage or
replacement may not be granted. Shipping claims must be made by the
consignee.

PLACEMENT

The SM Pro Audio CQ15/CQ31 utilizes an electronic circuit. Be sure that there
is enough air space around the unit for cooling. To avoid overheating, please do
not place the units on high temperature devices such as power amplifiers or
near other units, such as wireless, that may transmit high frequencies.

Mains voltage

The CQ15/CQ31 can be used with voltages ranging from 100V AC to 250V AC,
please make sure that you have selected the correct voltage range on the back
of the unit and that the required fuse setting is correct as well before switching
the unit ON. Any damage occurring as a result of incorrect voltage selection
may not be granted a warranty repair. A DC power supply is included.

CQ15/CQ32.

CQ15/CQ31 OVERVIEW

The CQ15 and CQ31 combination graphic equalizers / optical compressors offer
control over both frequency and level in a convenient single-space rackmount
format. The stereo CG15 and monophonic CQ31 are ideally suited for a variety of
live and installed sound applications, and are equally at home in the equipment
racks of bass players, keyboardists, and DJs.

SM PRO AUDIO CQ15/CQ31

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+ +
6 6

ON

3 3
0 0
3 3

OFF

6 6

POWER

- -

Channel A Channel B

+
12

6
0

+

12

-

6

+

6

-

12

- -

RANGE BYPASS LOW CUT

OPTICAL COMPRESSOR

RELEASE

COMP ATTACK BEQ

80Hz

INPUT L EVEL

AEQ

PEAK

+
12

6
0

+

12

-

6

+

6

-

12

RANGE BY PASS LOW CUT

OPTICAL COMPRESSOR

RELEASE

COMP ATTACK BEQ

80Hz

INPUT LEVEL

AEQ

CQ15

EQUALIZER

GRAPHIC

PEAK

Each of the CQ15’s two channels features 15 bands (2/3-octave) of equalization
with selectable ±6dB / ±12dB range. The compressors, one per channel and
available pre- or post-EQ (and featuring true circuit bypass) are designed to
address a variety of tasks, from harnessing troublesome peaks to putting a tight
low end on a stereo DJ mix.

OPTICAL COMPRESSOR

COMP ATTACK BEQ

+

12

­+

6

-

RANGE BYPASS LOW CUT

AEQ

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+
12

6

RELEASE

0
6

PEAK

12

80Hz

-

INPUT LEVEL

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+
6

ON

3
0
3
6

-

CQ31

GRAPHICEQUALIZER

OFF

POWER

When finer band-resolution is required, the CQ31 offers a full 31 bands
(1/3-octave) of equalization with selectable ±6dB / ±12dB range, topped off by
a fully adjustable optical compressor. As with the CQ15, the compressor is
available pre- or post-EQ and features true circuit bypass.

main features

• Stereo 15-band (CQ15) or monophonic 31-band (CQ31) graphic EQ

• Built in optical compressor / limiter per channel

• Selectable pre- / post-EQ compressor operation with true circuit bypass

• Balanced and unbalanced inputs and outputs

• Euro Block input and output connectors for fixed installations

• 1U rugged metal case construction

SM PRO AUDIO CQ15/CQ31

CQ15/CQ31 rear panel connections

Your CQ15/CQ31 is designed to accommodate a variety of balanced and
unbalanced audio connections, allowing for easy installation in both live and
studio environments.

CQ15 Inputs

• Channel A / Channel B Balanced XLR

• Channel A / Channel B Unbalanced 1/4” TRS

• Channel A / Channel B Balanced Euro Block

CQ15 Outputs

• Channel A / Channel B Balanced XLR

• Channel A / Channel B Unbalanced 1/4” TRS

• Channel A / Channel B Balanced Euro Block

INPUTOUTPUT

++ ++

CHANNEL B

CHANNEL A

INPUTOUTPUT

SMPROAUDIO Melbourne Australia Made in China

POWER INPUT

2

CQ31 Inputs

• Channel A Balanced XLR

• Channel A Unbalanced 1/4” TRS

• Channel A Balanced Euro Block

CQ31 Outputs

• Channel A Balanced XLR

• Channel A Unbalanced 1/4” TRS

XLR Pin Wiring

Pin 1: Common (shield / ground)
Pin 2: Positive
Pin 3: Negative

• Channel A Balanced Euro Block

IMPORTANT:

The CQ15/CQ31 accepts line level input signals upto +23dB. Do not
connect your power amplifier outputs to the CQ15/CQ31‘s inputs as this
will damage the internal circuitry and will not be covered under warranty!

INPUTOUTPUT

++

O

PRESSOR

E

0.3

0

1

50

0.2
2

100

0.1

3

RELEASE

CK BEQ

Hz
CUT

INPUT LEVEL

Graphic equalizer controls

The CQ15 features 15 adjustable frequency bands per channel spaced at
2/3-octave intervals. The CQ31 features 31 adjustable frequency bands
spaced at 1/3-octave. Both units offer the same complement of controls.

Faders

Raise the fader above the
0dB line to boost EQ at the
chosen band; lower the fader
to attenuate the EQ.

AEQ

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+

12

6
0
6

PEAK

12

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Range

Use to set the throw of the frequency band faders to ±6dB or ±12dB

+
6

ON

3
0
3

OFF

6

POWER

­Channel A

SM PRO AUDIO CQ15/CQ31

OPTICAL COMPR

COMP ATTACK

+

6

-

10

5

50

1

100

80Hz

ON

OFF

P

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+

12

6
0

+

12

-

6

12

-

RANGE BYPASS LOW CUT

+
6

3
0
3
6

-

Bypass

Removes the equalization
circuit from the audio path,
allowing the signal to pass
through unprocessed

+

12

­+

6

-

RANGE BYPASS LOW CUT

80Hz

PEAK

INPUT LEVEL

80Hz Low Cut

When enabled, filters out frequencies below 80Hz

Input Level

Use to adjust the level of the signal being routed to the equalization circuitry

Peak LED

Flashes on when source signal exceeds recommended input level

PEAK

SM PRO AUDIO CQ15/CQ31

optical compressor

The CQ15/CQ31 offers significantly greater functionality than traditional
graphic equalizers thanks to the inclusion of an optical compressor on each
audio channel. The compressor can be used to tame transient peaks without
needing to adjust the EQ, to tighten up the source signal’s low end, or to
smooth out a live mix—the applications are virtually limitless!

Comp

Use this rotary control to set the compression ratio. Ratio expresses the
constant difference between the input and output signal levels, with higher
ratios resulting in greater reductions in dynamic range. For example, a
compression ratio of 5:1 means that when the input level increases by 5dB,
the output level will increase by only 1dB.

Compression On/Off Switch & LED Indicator

Turns the compressor on or off. When off, the compression circuit is
completely removed from the signal path, i.e., true bypass.The LED shows
compressor’s on/off status.

Attack

Use to set the time (in milliseconds) it takes the compressor to respond to
the input signal and apply gain reduction. Set short attack times to control
the level of transients peaks. Longer attack times allow more signal to pass
through before the compressor engages, resulting in a punchier sound.

OPTICAL COMPRESSOR

10

5

1

50

100

COMP ATTACK BEQ

0.3

0.2

0.1

3

RELEASE

1

2

AEQ

optical compressor cont.’

Release
The release control sets the time (in seconds) that it takes for the
compressor to return to 0dB gain reduction in the absence of a source
signal. Short release times create a more exaggerated effect (”pumping
and breathing"), whereas long release times produce a more natural sound.

AEQ BEQ Switch and Status LED

Use this control to place the compressor in the signal path either before
(BEQ) or after (AEQ) the equalizer. When the status LED is illuminated, the
compressor is in AEQ mode.

Note that on the CQ15, all compressor setting are independent for each channel.

SM PRO AUDIO CQ15/CQ31

16k 16k10k 10k6.3k 6.3k4k 4k2.5k 2.5k1.6k 1.6k1k 1k630 630400 400250 250160 160100 10063 6340 4025 25
+ +
6 6

ON

3 3
0 0
3 3

OFF

6 6

POWER

- -

Channel A Channel B

+
12

6
0

+

12

-

6

+

6

-

12

- -

RANGE BYPASS LOW CUT

OPTICAL COMPRESSOR

0.3

0.2

0.1

RELEASE

COMP ATTACK BEQ

80Hz

INPUT LEVEL

AEQ

1

2

3

PEAK

+
12

6
0

+

12

-

6

+

-

12

RANGE BYPASS LOW CUT

OPTICAL COMPRESSOR

0.2

RELEASE

COMP ATTACK BEQ

6

80Hz

INPUT LEVEL

AEQ

0.3
1

2

0.1

3

CQ15

EQUALIZER

GRAPHIC

PEAK

Cq15/cq31 APPLICATIONs

Live Sound

The main use of a graphic equalizer in audio systems is to correct undesirable
anomalies in the overall sound, such reducing boominess in a venue that has
excessive low end response or adding some “sparkle” to a room that is overly
damped. A graphic EQ can also be used for overal “tone shaping,” which could
run the gamut from adding midrange definition vocals to refining the overall sound
of a mix. To a more limited extent, a graphic EQ can also be used to control feedback.

Since the CQ15 and CQ31 both include optical compressors, greater flexibility in
both signal processing and control is available. For example, you can boost high
frequencies to create clarity, while at the same time compressing the high
frequencies so that the occasional transient peak won’t harm your sound system
(or your audience’s ears!). You can also use the compressor to limit the dynamic
range of a live mix, while at the same time maintaining complete tonal control.

Bass and Guitar Rigs

EQs and compressors have long been staples in guitar and bass rigs. With the
CQ15/CQ31 you have the convenience of both processors in a single rackmount
unit. Dial in your tone with the EQ, then add punch and sustain with the compressor.

SM PRO AUDIO CQ15/CQ31

WARRANTY

SM Pro Audio warrants the mechanical and electronic components of this product to be
free of defects in material and workmanship for a period of one (1) year from the original
date of retail purchase, in accordance with the warranty regulations. If any defects occur
within the specified warranty period that are not caused by normal wear or inappropriate
use, SM Pro Audio shall, at its sole discretion, either repair or replace the product.

WARRANTY REGULATIONS

• Warranty is enforceable only by the original retail purchaser.

• Warranty services will be furnished only if the product is accompanied by an original retail
dealer’s invoice. Any product deemed eligible for repair or replacement by SM Pro Audio under
the terms of this warranty will be repaired or replaced at SM Pro Audio’s sole discretion.

• If the product needs to be modified or adapted in order to comply with applicable
technical or safety standards on a national or local level, in any country that is not the
country for which the product was originally developed and manufactured, this
modification/adaptation shall not be considered a defect in materials or workmanship.

• The warranty does not cover any such modification/adaptation, irrespective of whether it
was carried out properly or not. Under the terms of this warranty, SM Pro Audio shall not
be held responsible for any cost resulting from such a modification/adaptation.

• Free inspections, maintenance/repair work, and replacement of parts are expressly
excluded from this warranty, in particular if caused by inappropriate use. Likewise, the
warranty does not cover defects of expendable parts caused by normal wear of the product.
Expendable parts are typically pots, potentiometers, switches and similar components.

• Damages/defects caused by the following conditions are not covered by this warranty:
Misuse and/or abuse; Neglect or failure to operate the unit in compliance with the
instructions given in the user or service manuals; Connection or operation of the unit in
any way that does not comply with the technical or safety regulations applicable in the
country where the product is used;
beyond the control of SM Pro Audio.

Damages/defects that are caused by any other condition

• Repairs and modifications performed by unauthorized personnel will void the warranty.

• Products that do not meet the terms of this warranty will be repaired solely at the buyer's
expense. SM Pro Audio will inform the buyer of any such circumstance. If the buyer fails to
submit a written repair order within 4 weeks after notification, SM Pro Audio will return the
unit C.O.D. with a separate invoice for freight and packing. Such cost will also be invoiced
separately when the buyer has sent in a written repair order.

CLAIM FOR DAMAGES

Failure of SM Pro Audio to provide proper warranty service shall not entitle the buyer to
claim (consequential) damages. In no event shall the liability of SM Pro Audio exceed the
invoiced value of the product.

OTHER WARRANTY RIGHTS

This warranty does not exclude or limit the buyer's statutory rights provided by national
law, in particular, any such rights against the seller that arise from a legally effective
purchase contract.

RETURN AUTHORIZATION NUMBER

To obtain warranty service, you must contact SM Pro Audio for a Return Authorization
number before returning the product (Tel.: [phone]; [e-mail]).
All inquiries must be accompanied by a description of the problem. No products will be

accepted for warranty service without a Return Authorization number

The product must be returned in its original shipping carton, together with the Return
Authorization number, to:

SM Pro Audio Service Department, W25 26-28 Roberna St., Moorabbin, Melbourne,
Victoria, Australia 31892.

If the warranty claim proves to be justified, the product will be returned freight prepaid by
SM Pro Audio within Australia.

Outside of Australia, please contact you local distributor for a Return Authorization
number and shipping instructions.

CLAIM FOR DAMAGES

Failure of SM Pro Audio to provide proper warranty service shall not entitle the buyer to
claim (consequential) damages. In no event shall the liability of SM Pro Audio exceed the
invoiced value of the product.

CQ15 Features

• 2 x 15 Bands of Equalization

• Selectable ±6dB / ±12dB Fader Range per Channel

• Optical Compressor per Channel w/ Adjustable Input Level, Compression
Ratio, Attack, Release, and Selectable Pre-EQ / Post-EQ Operation

• 80Hz Low Cut Filter (per Channel)

• 2 x Balanced XLR Inputs

• 2 x Balanced / Unbalanced 1/4” TRS Inputs

• 2 x Balanced XLR Outputs

• 2 x Balanced / Unbalanced 1/4” TRS Outputs

• 2 x Balanced Euro Block Input / Output

SM PRO AUDIO CQ15/CQ31

SMPROAUDIO M-Patch 2

CQ31 Features

• 31 Bands of Equalization

• Selectable ±6dB / ±12dB Fader Range

• Optical Compressor w/ Adjustable Input Level, Compression Ratio,
Attack, Release, and Selectable Pre-EQ / Post-EQ Operation

• 80Hz Low Cut Filter

• 1 x Balanced XLR Input

• 1 x Balanced / Unbalanced 1/4” TRS Input

• 1 x Balanced XLR Output

• 1 x Balanced / Unbalanced 1/4” TRS Output

• 1 x Balanced Euro Block Input / Output

SM PRO AUDIO CQ15/CQ31

The information contained in this manual is subject to change without notice. No part of this manual may be reproduced
or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording of any kind,
for any purpose, without the express written permission of SM Pro Audio.

All Rights Reserved © 2011 SM Pro Audio

CQ15/CQ31

Graphic EQualizer + compressor

SM PRO AUDIO CQ15/CQ31

SMPROAUDIO M-Patch 2