dbx 1231 Dual 31-Band Graphic Equalizer

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.

dbx 1231 Features

• Switchable boost/cut ranges of ±6 or ±15 dB
• Electronically balanced/unbalanced inputs
• Servo balanced/unbalanced outputs
• RF filtered inputs and outputs
• XLR, Barrier Strip, and 1/4" TRS connectors
• -12dB/+12dB input gain range
• 18dB/octave 40Hz Bessel low-cut filter
• Chassis/signal ground lift capability
• Internal power supply transformer
• Power-off hardwire relay bypass with 2-second power-up delay

• 1231 dual 31-band graphic equalizer1
• AC power cord1
• Rack mount screws4
• Washers4

• Input Connectors1/4" TRS, female XLR (pin 2 hot), and barrier terminal strip
• Input Typeelectronically balanced/unbalanced, RF filtered
• Input Impedancebalanced 40 kOhm, unbalanced 20 kOhm
• Max Input>+21dBu balanced or unbalanced
• CMRR>40dB, typically >55dB at 1kHz
• Output Connectors1/4" TRS, male XLR (pin 2 hot), and barrier terminal strip
• Output Typeimpedance-balanced/unbalanced, RF filtered
• Output Impedancebalanced 200 Ω, unbalanced 100 Ω
• Max Output>+21dBu balanced/unbalanced into 2 kOhm or greater; >+18dBm balanced/unbalanced (into 600 ohm)
• Bandwidth20Hz to 20kHz, +0.5/-1dB
• Frequency Response<10Hz to >50kHz, +0.5/-3dB; +/-15dB range; +/-6dB range
• Dynamic Range109dB; 115dB
• Signal to Noise Ratio90dB, 97dB
• THD+Noise<0.005%
• Interchannel Crosstalk<-80db, 20Hz to 20kHz
• Bypass Switchbypasses the graphic equalizer section in the signal path
• Low Cut Switch(recessed) activates the 40Hz 18dB/octave Bessel high-pass filter
• Range Switch(recessed) selects either +/- 6dB or +/- 15dB slider boost/cut range
• I/O Meter4-LED bar graph (Green, Green, Yellow, Red) at -10, 0, +10, and +18dBu
• IndicatorsEQ Bypass (Red); Clip (Red); Low Cut (Red); +/-6dB (Yellow); +/-15dB (Red)
• Operating Voltage100VAC 50/60Hz; 120VAC 60Hz; 230VAC 50/60Hz
• Power Consumption24 W
• Power ConnectorIEC receptacle
• Dimensions (HxWxD)5.25" x 19" x 7.9"
• Weight10.6 pounds