Detailed Description  4 Channel Power Amplifier, Karaoke Amplifier, KTV Amplifier, PA Amplifier, Pro Amplifier,Sound Amplifier, Stereo Amplifier, Professional Amplifier, Professional Audio Amplifier, Disco Amplifier. P1800 Four Channel Power Amplifier 1KHz,Output Power (8Ω Stereo)  450W×4 Output Power (4Ω Stereo)  675W×4 Output Power (8Ω Bridged Mono) 1100W×2 Frequency Response(+0/-0.3dB,1W/8Ω)  20Hz-20KHz Power Bandwidth(rated power at 4Ω,1%THD+N) 20Hz-20KHz,+0/-0.2dB Tour Class Protection  Clip Limit,Soft Start,Temp,Short-Circuit, DC,infrasonic Input.  THD+N ( 8Ω/1KHz 1W )  SMPTE IMD(rated power,8Ω,60Hz&7KHz) Damping Factor(1000Hz at 8Ω )  248 Input CMRR(1KHz) 60dB Input Sensitivity(rated power at 8Ω)  1.6V  Voltage Gain X40dB Input Impedance(balanced/unbalanced) 20KΩ/10KΩ S/N  96.8dB Crosstalk -70dB Class H Net Weight (kg)  31.5 Cross Weight (kg)  35 Supply Power (W) 2800  Standard Power Supply  AC220V,50Hz LED Indicators(per channel)  Active, Protect, Signal, Critical Dimensions(H×W×D) 132×483×480mm (3U)