does anyone know about this amp. It's rated at 500 rms @ 4 ohms and 850@ 2 ohms. It's cea certified so it shuld be on the money right? I can pick one up for 159.95. What is the differance between say a kenwood and a kicker. if they both put out 800 @ 2 ohms and are cea ceritfied, why is one twice as much?