a buddy of mine bought a new deck,amp,speakers & subs for a total cost less then my amp,deck or speakers separately. the sound difference isn't all that for the price. So to rub it in he went and bought a secound amp, and two more subs. It sounds pretty good & bumps HARD !!! He's got way to much bass . So as I add & change my system around to show off quality equipment, that I've collected over the years. The next day I've got all of my best hooked up and sounding better then I've ever heard , In my own car. So all ready to show off what quality equipment & sound really Is. As get near his house he's allready out side looking down the street ,I pull in, let him in and turn it up, way up !!! He was impressed, but then I had to see what he did to his system sence I last saw it. ( too much bass ) he left the bass the same, & added a high output amp. for the mids and a new set of tweets..... Well it now sounds*** Better then mine !!! And then some !!! So a quick rundown of my system~ As follows~ Kenwood deck $675.00/ Infinty tweets, Infinty mids & Infinty 6x9s front & rear doors, JBL 6x9s back window. cost for speakers ??? $750.00 at least. 800 watt Pheniox Gold amp. $600.00 powering two 10 inch JBLs in a obcon bandpass box, speakers $250.00+ obcon box $275.00, two 12inch MTX Road Thunder speakers in separate boxes,$300.00 powered by two 1000watt Kenwood amps. $600.00, Also JVC high output amp, $250.00, Wiring,comp,crossovers,ect. total cost approx. $4000.00. His system~As follows~ JVC deck,installed,w/remote. $175.00, Four 5 1/4inch Kickers, Installed $160.00, Two 1000watt Sony Explode amps, $300.00, Four 12inch Kicker & two boxs, $350.00, Two pioneer tweets, $75.00, installed, 300watt pioneer high output amp. $90.00, wiring,comp,ect. total cost just over $1100.00.
I didn't see you list anything in your system to help compensate for the power draw on your car's alternator and battery. If you haven't added in any high-current capacitors or mods to your car's electrical system, I bet your four amps aren't getting anywhere near enough power. That would certainly explain poor performance from good gear.
Also, remember that the car itself can sometimes have a lot to do with sound quality. What kind of car do you and your nemesis have?
Another quick point, price is not always a clear indicator of performance. I've listened to sub 1000 dollar systems that outperform 5000 dollar systems, but I'll agree that most of the time, the more you spend, the better you get.