I have this amp and the 4.920 as well as the 1.500 Mono amp PLENTY OF CLEAN,CLEAN POWER... I have the Kenwood Excelon KDC-X997 Head Unit, AudioControl EQS 6 channel PRE AMP EQ, Sound Stream BX-20Z Bass Reconstructor ON ITS WAY>>Ground Shaker CP112 Sealed Box, Morel Primo 124 12" Sub, Fusion PPCM 650 Component as well as the Sound Stream RF 60 C Component
I am selling the 1.500 to a friend as the Single Morel is only 4 Ohms and the 2.640 will push 640 Watts into a single 4 Ohm load and the 4.920 is still overkill but its better to have too much clean power than not enough. BUT that brings me to another point... These Amps cannot be touched for what they are being sold for on here. These amps are not your average run of the mill 640 Watt and 920 Watt amps these are substantial ... they are heavy and large but they look INCREDIBLE IF I COULD GIVE MORE STARS I WOULD.
I matched this to a 12" Obsidian Subwoofer by bridging the sub to take advantage of the 640rms rating this amp has at 4ohm. What a wonderful choice. Tons of adjustments so that I could tailor the sound to exactly how I wanted it. Very powerful. I measured and it is putting out a bit more than advertised rating. Very clean signal. Properly adjusted this thing never gets hot. Plus I really like the understated styling. With 1 sub in the box and this amp powering it, I've rattled off my rear spoiler. Literally, it fell off. I absolutely love the Reference series amps. I hope that Soundstream replaces it with something of equal or better quality.