Upgrading Sound System
Today is my first day on the forum! Glad I joined, TONS of good info here.
I just recently updated my sound system. I have a 99 323i E36 Vert. Stock amp, stock speakers (10 speakers), aftermarket head unit. (The guy who put the head unit in got frustrated trying to hack into the stock system and only got the 2 speakers in the front kick panels to work. So I pulled the head unit and started over.) Here's my experience:
The stock speakers can only run from the stock amp as it has built in crossovers. If you try and run the stock speakers straight from an aftermarket head unit, you will not like the results, unless you are good at buying aftermarket crossovers and configuring them to the stock speakers. Just a pain.
Also, since the stock amp has built in crossovers, you will drive yourself nuts trying to figure out the wiring to make this work with aftermarket speakers. In addition, the stock amp is not 'adjustable' like aftermarket amps and again, you won't like the results.
It's just my opinion, but if you want a really nice system, just unhook (or remove) the stock amp and speakers and run all new. It's a bit of a DIY project but I did this and the results are AMAZING. Again, just my opinion, but the stock system is just not worth trying to hack into if you really want a nice system. If you shop around and Google for a while, you can do an entire new system for less than $800.
I bought a nice 6 channel amp and two sets of infinity Kappa separate component speakers with crossovers. One set for the front and one set for the rear. The amp and speakers were a total of $500. I also bought a 10 inch subwoofer (I went cheap here, for the time being) with a small enclosure for $100. The head unit the guy put in had pre-amp outputs for front, rear and sub. I ran all the RCA's to the trunk and ran all new speaker wires. Took me about 2 days of ripping the car apart and putting it all back together, but the results are WELL worth it.