I just did a complete system in my 02 Bonneville SSEi. I More or less moved my system from my 2DR Tahoe when I sold it, but my speakers were messed up so I warrentied them for Infinity Kappas.
When I bought the car, it had a Pioneer deck and Reference components (6.5") front and 6X9s rear. I yanked the deck and front speakers, wired 14awg to the doors from my 4 channel and wired up the power to my amps (Memphis 1000d for my two Image Dynamics IDQ10s, and a Diamond 400.4 for the speakers). I painstakingly installed the speakers and crossovers (those enormous tweeters are a PITA). I dont relly believe in rear speakers, so I just have them disconnected.
SO heres my problem. It sounds like complete and utter garbage. The mids are harsh, the lower mids are absent and the upper highs (just before the crossover) lack detail and can be harsh.
It sounds like baffle diffraction and a horn effect. In my car, the speakers mount to the interior panel, so it has a lame baffle to begin with, and theyre also recessed an inch and a half from the outside of the panel. Both are very bad for sound, so obvoiusly I want to address both issues. However, the refereces didn't sound this bad. What gives?
I'm bainstorming possible solutions to the problem. First, I want to build a fiberglass enclosure onto the door panel to give the driver an airspace of its own, stiffen the door panel and add weight to the baffle. The problem there is that I'd have to make it removeable. The driver is rear mount.
I dynamatted the doorskin, which made an aready very quiet car eirily silent. I think that doing the panel and door structure would be of help as well.
I still need to tune the filters on the amps, but its had when it sounds so bad.
Anyway, sorry for the long post. Any help here is much appreciated.