Loyola Enterprises

A veteran and minority owned SDB Certified Business.


DBX 2231

757.498.6118 Ext - 109DBX 2231 - Call for pricing - Dual 31 band EQ


PDFDBX 2231 Cut Sheet (pdf)

PDFDBX 20-Series Manual (pdf)

With a prestigious heritage extending back to the heralded 30 Series equalizers, the dbx 2231 easily lives up to the reverred dbx reputation. Besides including two 31-band channels of 1/3-octave equalization, the 2231 empowers you with flexible features like the PeakPlus™ limiter circuit, and the amazing Type III™ Noise Reduction system. It also includes ±12 dB input gain range; switchable ±6 or ±15 dB boost/cut range; XLR, Barrier strip, and ¼" inputs; nonconductive nylon sliders; and an intuitive user interfce with comprehensive output and gain reduction metering. As always, the inevitable result of dbx’s meticulous attention to detail and top-quality componentry is exceptional sound, performance, and reliability.

The most revolutionary feature of the 2231 is the proprietary Type III™ Noise Reduction system, which enables you to boost signal-to-noise ratios by up to an incredible 20 dB. The result of this instant encode/decode process is that you’re no longer forced to employ drastic EQ settings in effort to reduce system noise. Instead, you’re freed to dedicate all EQ bands to the most important thing, the music. Further, the PeakPlus™ limiter technology allows you to easily safeguard your gear against hazardous dynamic surges in program material. In addition to these formidable tools, the 2231’s front panel provides at-a-glance insight as to gain reduction and output level status via its four-stage LED ladders. With such power and finesse built into such a reasonably priced package, it’s easy to see why dbx 20 Series equalizers are relied upon by studio and touring professionals the world over. With such affordable quality, there’s no longer any excuse for compromising sound.


  • dbx’s revolutionary Type III™ Noise Reduction system, which increases S/N ratio by up to 20 dB
  • PeakPlus™ limiting technology with threshold range from 0 dBu to +24 dBu (off)
  • Two 31-band, 1/3-octave channels with switchable boost/cut ranges of ±6 or ±15 dB
  • ±12 dB input gain range
  • XLR, Barrier strip, and ¼" inputs
  • 4-segment LED ladders for monitoring of gain reduction and output levels—the most comprehensive visual feedback available
  • Exceptional sound quality
  • dbx’s unmatched engineering and construction standards

Connectors ¼" TRS, Female XLR (pin 2 hot), and barrier terminal strip
Type Electronically balanced/unbalanced, RF filtered
Impedance (bal./unbal.) 40 kΩ / 20 kΩ
Max. Input Level >+21dBu balanced or unbalanced
CMRR >40 dB, typically >55 dB at 1 kHz
Connector ¼" TRS, Male XLR (pin 2 hot), and barrier terminal strip
Type Impedance-balanced/unbalanced, RF filtered
Impedance (bal./unbal.) 200 Ω / 100 Ω
Max. Output Level >+21dBu balanced/unbalanced into 2kΩ or greater
>+20dBm balanced/unbalanced (into 600Ω)
System Performance
Bandwidth (±0.5dB) 20 Hz–20 kHz
Frequency Response (+0.5/-3dB) <10 Hz >50 kHz
Dynamic Range (±15dB/±6dB) >108 dB / >112 dB
Signal-to-Noise (±15dB/±6dB) >90 dB / >94 dB
THD+Noise @ 1 kHz <0.04%, 0.02% typical at +4 dBu
Interchannel Crosstalk (20–20k Hz) <-80 dB
Noise Reduction Up to 20dB of dynamic broadband noise reduction
Function Switches
Type III NR Activates dbx Type III Noise Reduction
EQ Bypass Bypasses the graphic equalizer section in the signal path
Low Cut Activates the 40 Hz 18dB/octave Bessel high-pass filter
Range Selects either ±6 dB or ±15 dB slider boost/cut range
Output Level 4-LED bar graph (Green, Green, Yellow, Red) at -10, 0, +10, and +18dBu
Gain Reduction 4-LED bar graph (all Red) at 0, 3, 6, and 10dB
Type III NR Active 1 LED: yellow
EQ Bypass 1 LED: red
Clip 1 LED: red
Low Cut 1 LED: red
±6 dB 1 LED: yellow
±15 dB 1 LED: red
Power Requirements 100-230V 50/60 Hz, 23 Watts
Weight 4.81 kg (10.6 lbs)
Dimensions (HxWxD) 13.3 x 48.3 x 20.1 cm (5.25" x 19.0" x 7.9")
For pricing options and packages, contact us at
757.498.6118 Ext - 109, Or