Basic Systems For The Impulse Six-Channel Amplifier; Front & Rear Speakers With Stereo Subwoofers*; Front & Rear Speakers With Bridged Mono Subwoofer(S)*; Front & Rear Crossovers Set To 70 Or 110Hz Highpass. Sub Crossover Set To 70 Or 110Hz Lowpass - Kicker Impulse 356xi Owner's Manual