231S Dual 31 Band Graphic Equalizer

The dbx 231s is a dual-channel graphic equalizer that gives you 31 bands of 1/3-octave Constant Q filtering per side. Constant Q keeps each filter's bandwidth consistent at any boost or cut setting, so pulling down a ringing frequency in a room does not drag its neighbors with it. The 20mm nonconductive sliders hold their position through load-in and load-out, and a switchable ±6 dB or ±12 dB range lets you choose between fine tuning a monitor path and making larger corrections in a difficult room.

A ±12 dB input gain control matches the 231s to the console or processor feeding it. Four-segment LED ladders on each channel show output level, so you can see headroom instead of guessing at it. The 50 Hz high-pass filter, switchable per channel at 12 dB/octave, clears stage rumble, air handling noise, and mic thumps before they reach the amplifiers. A front-panel bypass drops the EQ section out of the signal path for an instant comparison between processed and unprocessed sound.

Both XLR and 1/4" TRS connectors are provided on inputs and outputs, so the unit drops into a rack next to a mixer, crossover, or amplifier without adapters. Electronically balanced, RF-filtered inputs keep it quiet in venues full of wireless gear and dimmer packs.

Measured performance stays clear of the program material: response runs from below 10 Hz to above 50 kHz, dynamic range is typically greater than 112 dB, and THD+Noise sits under 0.003%. The 2U steel chassis fits any standard 19" rack and runs on 100-240 VAC, so the same unit travels internationally without a second power supply.