Well I was going to compose a thorough post about the upgrades I've done in my car, but with 2 out of 3 kids puking, and being distracted by the olympics, it boils down to this:
About 6 months ago I purchased this
Alpine deck to play my iPod on the road. No cd transport, but all my cd's are ripped to the iPod anyway. Relatively happy, except for two area's. The interface is not as simple and intuitive as the iPod itself, and the display is only 2 lines high. (And not wide enough). I'm used to it now, and I wasn't going to spend another $150 for the next model up.
I connected it to two old amps and a sub I had laying around from the pre-children days. Kept the factory Bose door speakers. (It's an Acura 3.2 TL) Sounded much better than stock, but still just OK.
Fast forward to this past Saturday, when I picked up this bad boy.
Alpine incorporated the Audyssey MultiEq for use in an automotive environment.
I ran a single sweep for the drivers seat only, sent the correction parameters to the module, and the results are amazing. The harshness is almost completely gone - notice the hole I had at 500Hz, and the overload at 1000Hz. And with the time corrections, I actually have a decent soundstage now. When I get more time, I will map multiple spots throughout the car but for now, I'm more than satisfied.
Here is the opening screen showing microphone placement:
Here are the before & after results: