The ARC XDi Class-D series is a great little line of amps. Very small footprint with good power. The 4 chnl can easily run 4-8 in-boats or bridge a pair 6.5" or 8" HLCDs for 240W rms each. The 3 and 5 chnl will also run some in-boats and offer up to 420W for 1 or 2 subs. The XDi1000.1 does 700W rms @ 2. Id love to see a more powerful 4 chnl though.