Five-Channel, Class D System Amplifier Inputs: Three Stereo Pairs (RCA-Type Jacks), Differential-Balanced Inputs On-board Crossover: Subwoofer Channel: 12 or 24dB/octave Low-Pass with continuously variable cutoff frequency selection from 50-500 Hz, defeatableChannels 1 & 2: 12dB/octave High-Pass with continuously variable cutoff frequency selection from 50-500 Hz or 500-5000 Hz (via x10 Switch), defeatableChannels 3 & 4: 12dB/octave High-Pass or Bandpass with continuously variable high-pass cutoff frequency from 50-500 Hz (low-pass cutoff of bandpass filter tracks with Ch 1&2 HP cutoff frequency), defeatable. Speaker output connections: Accept up to 8 AWG wire +12V and Ground connections: Accept up to 4 AWG wireNotes: NexD™ Ultra-High Speed Class D, Remote Level Control (Subwoofer Channel or All Channels), via Optional HD-RLC (Sold Separately).