from my experience, f**k the shops, every shop ive been to in south sac has nothin but dumb ass workers, maybe not dumb but def not educated in car audio, i had workers from shops ask ME whats rms? whats ohm load? whats this and that when im trying to ask them for specific stuff, they wanna say max this and best that, f**kin guy at shop was really tryin to persuade me his 1000 watt max lanzar was louder than my zapco ref 750 before, and he was soo serious too, thats whhy i dont let the shops do anythin to my ****, i try to figure it out myself and do it myself, and if i eff everything up, at least i know exactly who to be mad at.