The dbx® 12 Series were designed to meet the needs of the most demanding sound reinforcement environments, while offering the simplicity of straightforward controls and providing years of maintenance- free operation in any application. The magnetically- isolated transformer, electronically balanced inputs and servo balanced 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 2U steel/aluminum chassis. 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. The 12 Series EQs also offer: 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.