Well, this is my first review that I have submitted. I bought this sub amp a few years ago to turn my Optimus Radio Shack sub into a powered one. The sub cost $100, plus the $160 for the amp, and I think it performs admirably. Of course, the horrible thing about this hobby is that you can ALWAYS upgrade, as I am looking to do now. I am considering a Hsu sub, and I will report back if this amp can push something like that. We shall see.
In conclusion, although I have little to compare this sub amp to, I know it drastically improved the subs performance. It's not pretty, but it gets the job done.

I PURCHASED THIS SUBWOOFER AMP ABOUT 2 YEARS AGO TO POWER MY 18" FRANKENSTEIN SUBWOOFER. BY FRANKENSTEIN I MEAN AN OLD BSR SUBWOOFER IN WHICH THE SPEAKER AND CROSSOVER WERE BLOWN OUT. I REPLACED THE SUBWOOFER SPEAKER WITH A JBL MODEL AND THE CROSSOVER WITH ONE PURCHASED FROM MCM ELECTRONICS. I ALSO HAD THE HOUSING LAMINATED WITH FORMICA TO MATCH MY LIVING ROOM SET, SO I WAS VERY RELUCTANT TO REPLACE IT. I AM CURRENTLY DRIVING MY PARADIGM TITANS THROUGH AN ONKYO 45 WATT PER CHANNEL RECEIVER THAT SOUNDS GREAT FOR ITS POWER RATING. I HAVE MY FRANKENSTEIN SUBWOOFER DRIVEN BY THE DBX-XB150 PROVIDING THE LOW END. OBVIOUSLY, WITHOUT THE SUBWOOFER AMP THE 45 WATT RECEIVER, ALTHOUGH UNDER POWERED IN ITS POWER RATING AND WELL CAPABLE OF HANDLING IMPEDANCE TO 2 OHMS, CANNOT SUFFICIENTLY DRIVE AN 18" SUBWOOFER. THE END RESULT IS A MUCH MORE STABLE AND THICK BASS OUTPUT BY THE FRANKENSTEIN SUBWOOFER. THE SOUND IS CLEAN AND THE TRANSIENTS ARE RESPONSIVE. THE UNIT DOES LACK AN ADJUSTABLE CROSSOVER, SO THE SATELLITE SPEAKERS DON'T MATCH AS WELL AS THEY SHOULD. ANY PERSON WHO WOULD BUY A SUBWOOFER AMP IS EITHER LOOKING TO FREE UP MORE POWER FROM THEIR MAIN AMP AND GAIN OVERALL VOLUME OR LOOKING TO REPLACE OR UPGRADE THEIR PRESENT SUBWOOFER POWER SOURCE. WITH THAT IN MIND THIS AMP DOES JUST THAT AND AT $159 FROM J AND R IT MAY JUST BUY YOU ENOUGH TIME TO HOLD YOU OVER UNTIL YOU REPLACE THE SUBWOOFER ALTOGETHER WITH A NEW POWERED ONE. THIS PRODUCT IS NOT A AUDIO MARVEL BUT RATHER A PRAGMATIC ONE. IT DOES THE JOB REAL WELL.