i have the beast and now i would like to test her out. i have had my eye on the 15 xxx by re. this comes in a dual 2, quad 2, and dual 1 ohm model. what i am wondering is what would be the optimum spl with the safety of the amp and sub considered.
it puts out 800 watts RMS @ 2 ohms bridged. that's not really enough power for a XXX 15" to be honest. It'd be good for maybe an SE or SX. for one sub, pay the $25 fee and order the custom coil setup of dual 4 ohm coils. that'll give you a 2 ohm load.
I don't know what generation your 2100HCCA is, but the first and second gen amps at least, were only stable to 1 ohm stereo, 2 ohms bridged. 800 watts RMS total either way
the only HCCA amp that was .5 ohm stable in the first two generations was the 225HCCA. The G3 and G4 series, I think, were .5 ohm stable stereo on other models as well, such as the 250HCCA and perhaps 275HCCA.
lots of amps in the 1200-1500 watt range in that price bracket. Just find a decent class D amp in that power range. Memphis has one, Hifonics, Crossfire, DEI has several, JBL... mostly it'll depend on features and looks beyond that