DOD SR231Q Specifications

GRAPHIC EQUALIZER

SR231

Dual 31-Band Constant Q Equalizer

The DOD SR231Q is a powerful 2 rack space
stereo/dual mono 31-band graphic equalizer of
uncompromising quality, performance, and features.
It allows the user to see a graphic representation of
equalization applied to the audio spectrum of a
sound source, and offers the flexibility to provide
solutions to many EQ problems. The SR231Q offers
up to 12 dB of cut or boost per band, and switch­able low cut filters for each channel. Electronic fil­ter switching minimizes transients (loud pops or
clicks when the switch is depressed), and up to

±12 dB of level control is available to compensate
for gain changes due to equalization boost or cut.
Constant Q constant bandwidth from each filter
throughout the full audio spectrum. The SR231Q
can be used as a stereo equalizer or as two inde­pendent channels of equalization, providing maxi­mum flexibility for all sound systems. Connections
to the SR231Q may be either impedance balanced
(1/4" tip-ring-sleeve phone plug) or unbalanced
(mono 1/4" phone plug) with XLR connectors avail­able as a factory option.

Low Cut Filter: 12 dB/octave rolloff, 3 dB down @ 50 Hz,
switchable in or out.

Frequency Response: 20 Hz-20 kHz, ±0/-0.5 dB.
Frequency Center Tolerance: 5%.
Slider Control Range: 12 dB cut/boost.
Input Impedance: 40kΩ balanced, 20kΩ unbalanced.
Maximum Input Level: +21 dBu.

Output Impedance: 102Ω balanced, 51Ω unbalanced.
Maximum Output Level:+21 dBu.
Input Gain Control: ±12 dB.
Harmonic Distortion: 0.004% at 1 kHz typical.
Signal-To-Noise Ratio: Greater than 90 dB.
Note: 0 dBu = 0.775 Vrms.
Input Common Mode Rejection: >75 dB@60Hz

SPECIFICATIONS

• 31 1/3 Octave Standard ISO Center
Frequencies Bands per channel

• Constant Q Filter

• 12dB of Boost/Cut per Band using Low
Noise Potentiometers

• LED Bargraph Level Indicators

• Low Cut and EQ In/Out Switches with
LED Indicators

• Balanced/Unbalanced input and
impedance bal/unbal outputs for each

channel

• Front Panel Power Switch

• 1/4" Phone connectors (XLR Optional)

• 2 Unit Rack Space

• One Year Limited Warranty

A Harman International Company

8760 South Sandy Parkway, Sandy, Utah 84070 • [phone] • Fax [phone] • Int'l Fax [phone] • Visit DOD on the World Wide Web at www.dod.com

GRAPHIC EQUALIZER

SR231

The graphic equalizer
shall be a two-channel 31­band type with frequency
centers on standard ISO
one-third octave frequen­cies with 12 dB of boost
and cut for each slider.
Equalization sliders shall
have a center detent at 0
dB with a protective dust
cover behind the front
panel. Low-noise sliders
shall be utilized having a
travel of 20 mm. Each
channel shall have a slider
input gain control with +/­12 dB range with center
detent at 0 dB. Bypassing
each EQ channel shall be
accomplished by a front­panel switch utilizing elec­tronic FET switching to
avoid transients and shall
have an LED to indicate
that the EQ is in. A front­panel low-cut filter per
channel at 50 Hz with 12 dB/
octave slope shall incorpo­rate electronic FET switch­ing and shall have an LED to
indicate that the filter is
engaged. Output level shall
be monitored on each channel by a four-LED peak-reading bar graph
calibrated to read -10, 0 +10, and +17 dBu.

The input section shall have one input per channel—electronical­ly balanced/unbalanced 1/4" TRS jacks (optional electronically bal­anced/unbalanced 1/4" TRS and XLR jacks) The output section shall
have one output per channel—impedance balanced/unbalanced 1/4"
TRS jacks (optional impedance balanced/unbalanced 1/4" TRS and bal­anced XLR jacks).

A front-panel rocker-type power switch shall provide visual indi­cation with red marking. The power supply shall be internal with two
thermally-fused transformers mounted in low hum orientations. The
transformers and primary side of the power supply shall be isolated
from the secondary and electronics by means of a steel hum isolation
shield. The power cord shall be detachable from an international stan­dard IEC 320 power inlet receptacle. Unit shall be constructed to
meet or exceed all applicable international safety and regulatory agen­cies. Unit shall be powered from 120 VAC 60 Hz (or 100 VAC 50/60
Hz, 230 VAC 50 Hz, 240 VAC 50 Hz). Unit housing shall be of all steel
construction and shall be rack-mountable in an IEC standard 19" rack
and shall occupy a 2U (3.5") rack space. An optional security cover
must be available.

The unit shall be a DOD SR231Q (or SR231QXLR) Graphic
Equalizer.

SR231Q

Notes

ARCHITECT & ENGINEER SPECIFICATIONS

#18-1701-A