BA-2600 Bass / Treble control2 OHM Stereo stableBridgeableProtection circuit for thermal, Sp short, DC reverse, DC offsetPWM mosfet power supplyBass Boost 6dB / 12dBLow pass variable crossover 40 ~ 240HzVariable subsonic filter 15 ~ 30Hz BA-4600 2CH/3CH/4CHoperationalBass Boost 6dB / 12dBProtection circuit for thermal, Sp short, DC reverse, DC offsetPWM mosfet power supplyLow pass variable crossover 40 ~ 240HzHigh pass variable crossover 40 ~ 240Hz