I can't find where the amp is in my 1993 318i. I'm getting some component speakers and would like to replace the stock amplifier with the crossovers. Do the 318's even have external amplifiers? Everyone says that the stock amp has internal crossovers, but my tweeters have a capacitor on them already. Whats the need for that capacitor if the amplifier has a crossover?

On my '93 325i with 10 speakers (non-HK), the amplifier is behind the left (driver's) side trunk trim panel. To get there, remove the trunk carpet, forward trim (on back of rear seat), LR speaker, and the plastic trunk floor panel left of the spare tire well. Getting the LH trim panel out takes some pulling, grunting and swearing, but there are no retention devices.

'93 318 = 6 speaker system = no external amp

Thanks for your help guys. I knew for a fact there there wasn't a crossover, because I hooked up a full range driver to the leads for the tweeter, and I got bass.

from what someone with a 93 told me, i believe it was dfrost, the filters are actually on the speakers...i will take BimwadM42's word that there is no amp in that car but i do know for a fact that the 93 325 does have an amp....
Kevin

On early '93's with the 10 speaker setup, there is no REAR crossover in the amp (only two leads to rear Nokia module). Front speakers apparently have crossovers in the amp, since there are separate outputs to each front driver. Don't know when the early/late cutoff happened, but the wiring diagrams in Bentley clearly show the difference (and a capacitor in the early '93 rear speakers). A quick look at the number of wires at the rear modules would show which you have.

I'm planning to do a test this weekend to determine the frequency range of my cone-type door mids, so I'll have an idea of what my factory amp crossover frequencies are.

Anybody know the impedance of the factory front speakers?

i BELIEVE they are 4ohms....i dont have the 93 with me to check now tho :(...remember to lemme know what u find man....
Kevin

I'll post the results next week.

I made a test CD with .wav files downloaded from Marks' Car Stereo Page at:

http://users.netmatters.co.uk/mea/index.html

So I have swept sine wave tones for 20-125 Hz, 125 Hz-1 kHz, 1-5 kHz, and 5-20 kHz. I'll use those to get an idea what frequencies are coming through each front driver. I don't have a sound meter or oscilloscope, so the results won't be precise.

cool :)
Kevin

I have the early 93 318i and it does measure at 4 ohms. I just rewired it with the Polk crossover that comes with the component speakers I bought.

Steve:
thanks for confirming.... :) and hope your polks sound good....
Kevin

Thanks Kevin, very well worth it!!!

Steve