When the pros need an EQ, they turn to dbx. With a proven track record that spans four decades, dbx EQs are the industry standard for touring, studios, and audio installations. With the dbx heritage of revered pro EQs, the 231s meets the needs of the most demanding sound reinforcement environments, while offering the simplicity of straightforward controls.
 
The dbx 231s includes two 31-band channels of 1/3-octave equalization, ±12 dB input gain, switchable ±6 dB or ±12 dB boost/cut range, 20mm nonconductive sliders, an intuitive user interface, and output level metering. From its extended 10Hz to 50kHz frequency response and 112 dB dynamic range to the quality componentry and meticulous attention to detail, the 231s offers exceptional sound and rugged reliability that guarantees you will always sound your best.
Sure to find a home in the studio, on tour and with installed sound venues, the dbx 231s is destined to take its rightful place in the lineage of great dbx signal processors that are the professional's choice in signal processing. With such affordable quality, there's no longer any excuse for compromising your sound.

The Features
- Dual 31-band, 1/3-octave Constant Q frequency bands
- Switchable boost/cut ranges of ±6 or ±12 dB
- Front panel bypass switch
- ±12 dB input gain range
- 4-segment LED ladders for monitoring output levels
- XLR and TRS Inpts and Outputs
- Frequency Repsonse of <10Hz to >50kHz
- Dynamic range of greater than 108dB

The Specs
The Input
Connectors 
1/4" TRS, female XLR (pin 2 hot)
Type
Electronically balanced/unbalanced, RF filtered
Impedance
Balanced 40k ohm, unbalanced 20k ohm
Max Input Level 
>+21dBu balanced or unbalanced
CMRR 
>40dB, typically >55dB at 1kHz
 
Outputs
Connectors
1/4" TRS, male XLR (pin 2 hot)
Type
Impedance-balanaced/unbalanced, RF filtered
Impedance
Balanced 100 ohm, unbalanced 50 ohm
Max Output Level 
>+21dBu balanced/unbalanced into 2k ohm or greater
>+18dBm balanced/unbalanced (into 600 ohm)
 
System Performance
Bandwidth
20Hz to 20kHz, +0.5/-1dB
Frequency Response
<10Hz to >50kHz, +0.5/-3dB
Dynamic Range
Typicall >112dB
Signal-to-Noise
Typically >95dB
THD+Noise
<0.003%
Interchannel Crosstalk 
<-90dB, 20Hz to 20kHz
 
Function Switches
EQ Bypass
Bypasses the graphic equalizer section in the signal path
Low Cut
Activates the 50Hz 12dB/octave high-pass filter
Range
Selects either +/- 6dB or +/- 12dB slider boost/cut range
 
Power Supply
Operating Voltage
100VAC-240VAC 50/60Hz
Power consumption
15W
Mains Connection
IEC receptacle
 
Physical 
Weight
6.2 lbs.(2.81 kg)
Shipping weight
7.9 lbs.(3.58kg)
Dimensions
3.5" (8.9cm) H x 6"(15.24cm) D x 19" (48.26cm) W