Used DBX 1231 Graphic Equalizer
Used DBX 1231 Graphic Equalizer units are dual-channel, 31-band graphic equalisers built for portable and touring applications, offering switchable boost/cut ranges, RF-filtered connections and a robust 3U steel/aluminium chassis. Second-hand examples of this well-regarded 12 Series equaliser are a popular choice for professional installations. Browse the current used DBX 1231 listings available on 10K Used by scrolling down.
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DBX 1231 Graphic Equalizer specifications
| Brand | DBX |
| Segment | Audio |
About the DBX 1231 Graphic Equalizer
The DBX 1231 Graphic Equalizer features dual channels with 31 one-third octave bands at ISO frequency centres, 45 mm faders, and a selectable boost/cut range of either plus or minus 6 dB or plus or minus 15 dB for precise gain adjustments. A switchable 40 Hz, 18 dB per octave Bessel low-cut filter and a plus or minus 12 dB input gain range add further control. Connectivity includes XLR, barrier strip and quarter-inch TRS connectors, with electronically balanced/unbalanced inputs, servo balanced/unbalanced outputs, and chassis/signal ground lift for hum isolation. Specified performance includes a 10 Hz to 50 kHz frequency response, greater than 90 dB SNR, less than 0.005% THD plus noise, and interchannel crosstalk below minus 80 dB. A power-off hardwire relay bypass with a two-second power-up delay supports reliable installation use. The 12 Series is recommended for portable and touring applications.
DBX 1231 Graphic Equalizer — buyer FAQs
What is the DBX 1231 Graphic Equalizer and what is it designed for?
The DBX 1231 is a dual-channel, 31-band graphic equaliser with one-third octave bands at ISO frequency centres, housed in a 3U steel and aluminium chassis. It is recommended for portable and touring applications. Key design choices, including RF-filtered inputs and outputs, a power-off hardwire relay bypass with a two-second power-up delay, and magnetically isolated transformer, reflect its suitability for demanding live and installation environments.
What connectivity options does the DBX 1231 offer?
The 1231 provides XLR, barrier strip and quarter-inch TRS connectors, covering a wide range of installation and live-sound wiring needs. Inputs are electronically balanced or unbalanced, and outputs are servo balanced or unbalanced. A chassis and signal ground lift capability is also included to help quickly isolate hum when integrating the unit into a system.
What are the key performance specifications of the DBX 1231?
The 1231 is specified with a 10 Hz to 50 kHz frequency response, greater than 90 dB signal-to-noise ratio referenced to plus 4 dBu, less than 0.005% THD plus noise at 1 kHz and plus 4 dBu, and interchannel crosstalk below minus 80 dB from 20 Hz to 20 kHz. The boost and cut range is switchable between plus or minus 6 dB and plus or minus 15 dB, with 45 mm faders providing hands-on control.
Who makes the DBX 1231 and where does it sit in the DBX range?
DBX is an American professional audio company founded in 1971, known for signal-processing equipment including compressors, equalisers and noise reduction systems. It is a brand of Harman International. The 1231 sits within the DBX 12 Series of equalisers, a line precision-engineered for maintenance-free operation across portable, touring and permanent installation use.
What should I check when buying a used DBX 1231?
Check that all 31 faders per channel move smoothly and without crackling, that the switchable boost/cut ranges engage correctly, and that XLR and TRS connectors are undamaged. Confirm the low-cut filter switches function and that ground lift operates as expected. Used units on 10K Used carry a 21-day warranty covering major functional faults; full guidance is in the buying guide at https://www.10kused.com/used-av-equipment-guide/.
