How should my car audio system be set up?

[That guy]

A couple years ago I bought 2 sets of Alpine Type S speakers 5x7, an Alpine CDA-9883 deck, and a 4 channel Alpine MRP-F250 amp for the speakers. A year later I bought a 12" Alpine Type R sub, with an Alpine MRP-M450 mono amp and a capacitor (I drive a 2006, 4 door, standard Ford Focus). Stupidly, I had Best Buy install all this equipment, and it has never sounded as good as I would have liked or expected. After showing the system to a new coworker who used to work at a small car electronics store, he checked the mono amp on the sub and told me it "was set to 0." I assume he was talking about gain. He also said that having seen the way Best Buy usually installs electronics the whole system is probably running inefficiently to the point where the 4 channel amp is probably not powering the speakers at all because of a wiring harness issue (or something like that). Anyway, if I go back to Best Buy to complain about their lousy job (and write a note to the Better Business Bureau) what kind of things should I call them on? What should the dials/gauges be set at and how should the wiring actually be set up? Whether intentional or not, they installed my 4 channel amp under the passenger seat with the knobs on the inside so I can't get at them. I don't want to shell out $500+ to get a real car audio place to reinstall everything but I don't have enough audio knowledge to go into Best Buy and call out their lies. My coworker has offered to do the work for me at the cost of parts, but I want it professionally done so everything can stay warrantied.

[doeboy579]

no one is going to be able to tell you how to set your gain corectly without you know the basics of car audio , for instance you may not know what clipping sounds like nor may you know at what point distortion will apper. now all i can sugjest is that you log on to cruchfield and do some reading. you should be able to tune your amp and set gains properly if you spend some time readind about these things. I'm not trying to be rude but once you know how things should be wire and tuned. then you'll be in a better position to walk into Best Buy and tell them everthing they did wrong.

[doeboy579]

no one is going to be able to tell you how to set your gain corectly without you know the basics of car audio , for instance you may not know what clipping sounds like nor may you know at what point distortion will apper. now all i can sugjest is that you log on to cruchfield and do some reading. you should be able to tune your amp and set gains properly if you spend some time readind about these things. I'm not trying to be rude but once you know how things should be wire and tuned. then you'll be in a better position to walk into Best Buy and tell them everthing they did wrong.