I'm having an ordinay Dolby Digital receiver which outputs 600W. Id like to get some improved amount of watts for the other speakers and especially for the sub woofer. Receiver has ordinary 5 channel outs and subwoofer out. Also has a purple color subwoofer out RCA socket. What equipment should I search for? I searched for an amplifier, however those come with minimum 2 channels. I'm looking for 1 channel amplifier for my subwoofer. Am I doing my research correct? P.S: Additionally I've seen people use best of the best AVRs on the market like Onkyo, Yamaha, etc. However when I check those specs, every unit's sound output is some what between 300W-800W. So I'm wondering how those folks are increasing the loudness of their systems to match with the room. Definitely 300W, 500W not enough for the job. I just need to know technically how to achieve that. You might say, use and amplifier. So normally should I find an amplifier which has 6 channel ins and 6 Chanel out?