1231 Dual 31-band, 1/3-octave Constant Q frequency bands - Image

Dual 31-band, 1/3-octave Constant Q frequency bands

The 1231 offers allows true 1/3-octave bandwidth control at all slider positions.

1231 Switchable boost/cut ranges of ±6 or ±15dB - Image

Switchable boost/cut ranges of ±6 or ±15dB

The 1231 features a boost/cut switch that allows you to select which of the two boost/cut ranges the equalizer will use, either ±6 dB or ±15 dB. The red LED lights when the ±15dB range is selected, and the yellow LED lights when the ±6dB range is selected. Note that the BOOST/CUT switch is slightly recessed. This is to prevent accidental activation of the switch, possibly causing damage to other sound system components.

1231 Bypass switch - Image

Bypass switch

Bypass the EQ with a simple press of the 1231's bypass switch that is conveniently located on the front panel.

1231 ±12 dB input gain range - Image

±12 dB input gain range

The 1231 is capable of -12 dB to +12 dB of gain.

1231 4-segment LED ladders for monitoring output levels - Image

4-segment LED ladders for monitoring output levels

The four Output Level LEDs indicate output level of the equalizer. The red LED is 3dB below clipping and is marked as +18dBu. It monitors the level at the output of the equalizer after all other processing.

1231 XLR and TRS Inputs and Outputs - Image

XLR and TRS Inputs and Outputs

The 1231 has balanced inputs and outputs that can be used with any balanced or unbalanced line-level device.

1231 Frequency Response of <10Hz to >50kHz - Image

Frequency Response of <10Hz to >50kHz

The 1231 is able to easily respond and adjust for a speaker's frequency response based on its amazing 10 Hz to 50 kHz frequency response range.

1231 18dB/octave 40Hz Bessel Low-Cut filter - Image

18dB/octave 40Hz Bessel Low-Cut filter

The 12 Series feature a 40Hz 18dB/octave Bessel high-pass filter used to reduce rumble or stage vibrations. The LOW-CUT switch inserts or removes the 18dB/octave 40Hz Bessel low-cut filter from the signal path. When the LOW-CUT switch is pushed in, the LOW-CUT filter is IN the audio path.

Specs & Downloads

Item# DBX1231V


Visionary design, revolutionary engineering

The dbx® 12 Series were designed to meet the needs of the most demanding sound reinforcement environments, while offering the simplicity of straightforward controls. The 1231 provides standard features like dual-channels, 31 1/3 octave bands, ISO frequency centers, +/- 12 dB input gain range, and switchable 40Hz/18 dB per octave low-cut filters, but also includes other insightful features. These include 45 mm faders; selectable +/-6dB or +/-15dB boost/cut range for precise gain adjustments; XLR, barrier strip, and 1/4'' TRS connectors for installation ease; balanced inputs and outputs for quiet operation; and chassis/signal ground lift capabilities for quick hum isolation. The visionary design of the dbx 12 Series makes your job easier. The dbx 12 Series Equalizers were precision engineered to provide years of maintenance-free operation in any application. The magnetically isolated transformer, electronically balanced/unbalanced inputs and servo balanced/unbalanced outputs, RF-filtered inputs and outputs, and power-off hard-wire relay bypass with 2 second power up delay were steps our engineers took to ensure compatibility for all installations. Only the best components were utilized, yielding a 10Hz to 50kHz frequency response, greater than 90dB SNR (ref +4dBu), less than 0.005% THD +Noise (1kHz at +4dBu), and interchannel crosstalk of less than -80dB from 20Hz to 20kHz. All this attention to detail is contained in a 3U steel/aluminum chassis.

General Specifications

Max Output
">+21dBu balanced/unbalanced into 2kΩ or greater >+18dBm balanced/unbalanced (into 600Ω)"
20Hz to 20kHz, +0.5/-1dB
Frequency Response
<10Hz to >50kHz, +0.5/-3dB
Dynamic Range
109dB @ +/- 15dB Range; 115dB @ +/-6dB Range
Signal to Noise Ratio
90dB @ +/- 15dB Range; 97dB @ +/-6dB Range
Interchannel Crosstalk
<-80dB, 20Hz to 20kHz
Bypass Switch
Bypasses the graphic equalizer section in the signal path
Low cut Switch
Activates the 40Hz 18dB/octave Bessel high-pass filter
Range Switch
Selects either +/- 6dB or +/- 15dB slider boost/cut range
Operating Voltage
100VAC 50/60Hz, 120VAC 60Hz, 230VAC 50/60Hz
Power Consumption
Power Connector
IEC receptacle
Weight (lb)

Audio Specifications

Input Connectors
1/4" TRS, female XLR (pin 2 hot), and barrier terminal strip
Input Type
Electronically balanced/unbalanced, RF filtered
Input Impedance
Balanced 40kΩ, unbalanced 20kΩ
Max Input
>+21dBu balanced or unbalanced
>40dB, typically >55dB at 1kHz
Output Connectors
1/4" TRS, male XLR (pin 2 hot), and barrier terminal strip
Output Type
Impedance-balanced/unbalanced, RF filtered
Output Impedance
Balanced 200Ω, unbalanced 100Ω


10.6 lb (4.8 kg)
5.25 in (13.4 cm)
7.9 in (20.1 cm)
19 in (48.26 cm)

What's in The Box?

  • 1 x dbx 1231 dual channel 31 band graphic equalizer
  • 1 x AC power cord
  • 1 x Operation manual
  • 1 x Registration card
  • 4 x Rack mount screws and washers

Documents & Downloads

Reviews and Q&A

Customer Reviews

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