Point taken regarding original poster and the built-in subs. I have used my 60 watt ARC amp exensively with 2s, 3s, and 5s, with roughly the same loudness results. It looks like the rated sensitivity and power recommendations are about the same for the 5 and 2CeSig2 (40 to 200 watts for the 5, 40 to 160 watts for the 2CeSig2).