I'm getting a sub/amp setup for my car, and am trying to decide between a few amps. For each, I'd be sending 2 channels to my 2 Rockford Fosgate HPC2206 Coaxial Speakers, which are rated at 75 W RMS (all Wattage figures are RMS) The first is a Rockford Fosgate P4004. It's the 2004 model: 50W x 4 Channels @ 4 Ohms 200W x 2 Channels Bridged @ 4 Ohms Cost is about $250 The second is a Rockford Fosgate Power 551X. I think its the 2002 model: 70W x 4 Channels @ 4 Ohms 275 W x 2 Channels Bridged @ 4 Ohms Cost is about $250 The third is an Audiobahn A6004T, 2003 or 2004 model: 75W x 4 Channels @ 4 Ohms 300W x 2 Channels Bridged @ 4 Ohms Cost is about $175 I don't know much about the SQ differences between the Audiobahn and the Rockford P4004. I'm pretty sure the 551X would be the best of the 3, but the cost is also higher because I'd need to get subs that could handle 300 Watts RMS. This is also the case with the Audiobahn. Does anyone have any opinions regarding which Amp would be the best value/performance? Also, I can get an Audiobahn 10" subwoofer, in a bandpass box, for about $90 including shipping. It's supposedly rated for 300 Watts RMS. Does anyone know anything about the quality of this sub/box?