2002 e39 Amp Replacement

[Andy60]

Hello all. My 2002 e39 has the factory Alpine amp (non-DSP). It is past time to replace the amp, and I intend to replace it with a 5-channel Pioneer. I will use the existing factory speakers. As I understand it, the Alpine has the cross-overs built into the amp. I have the wiring diagrams. But I also know each door has a circuit board in it which the speakers feed off. If the cross-overs are in the amp, what is the purpose of the circuit board? Can I simply connect the various wires directly to the amp? In other words, is the circuit board in the doors simply a passive "junction box?"

Also (and this is a tough one), do any of you happen to know the crossover points for the various door speakers?

Thanks.

Andy

[JimLev]

With the crossovers in the factory amp what are you going to use for crossovers.
I may have crossover frequencies info around here somewhere. Replace my amp and speakers a long time ago.
Yes, those circuit boards are just connection points the speakers plugin to.

[Twistytee]

I did the same with a 5 channel Alpine amp. The factory mids and woofers are relatively low watt, low quality and not particularly efficient speakers. So you’ll get more out of that amp by replacing the speakers. I went with 2 way components and a passive crossover upfront and coaxials in the rear deck. You can turn off the amp crossover for the fronts and use the sub crossover on the amp to power your bass. I bought all the gear used except for the sub and it sounds worlds better than the factory set-up. I also retained all of the factory twisted pair wiring for the speakers as it’s high quality and reduced the need to run a lot of cable/wire for me.

[JimLev]

Here's the frequency response from the output of the amp for the woofer, mid, and tweeter.
I measured these with a scope using a signal generator for the input.

FreqResponseOEM amp.JPG

[balidawg]

Factory speakers are likely long worn out by now. I would upgrade those first, then decide if you want a new amp.

[easymoney]

Factory speakers are likely long worn out by now. I would upgrade those first, then decide if you want a new amp.

I wouldn't doubt that. I replaced mine with Hertz all around a few months ago and am satisfied with them. What a big difference that is.

[JimLev]

I first replaced the speakers which was a good improvement, but the OEM would clip when you cranked it up.
A 100w/ch JL Audio amp fixed that.

[nsticka]

Factory speakers are likely long worn out by now. I would upgrade those first, then decide if you want a new amp.

I replaced all my factory speakers with Bavsound stage 1 kit..No noticeable improvement...I have non dsp, non nav as well.

[balidawg]

I replaced all my factory speakers with Bavsound stage 1 kit..No noticeable improvement...I have non dsp, non nav as well.

Good to know.

[BimmrMeUpSnotty]

Anyone have a spare 16x9 nav unit bezel trim plate laying around they wanna let go of, please let me know. I got the typical trim plate that you get for double din aftermarket installs, can't stand it, it's the one with the hood that sticks out on top. Sorry for the hijack....