Wiring New Stereo and Amp '94 32I

[Eric-325I]

Hello Friends:

The title says it all... I have searched this forum and found some good info but still need some help...

My daily is a great little 325I with a very tired factory stereo. Going to replace that with an Alpine head unit. Would also like to replace the factory amp at the same time... Here's the hard part: I will buy an Alpine amp but what type do I need? My car has two small speakers in each door, one in each lower front kick panel, and two on the rear deck... That's 4 on each side of the car (left/right)... So do I need a 4 channel amp then? And will I be able to basically pull the old amp out and 'plug' the new one in ( to the wiring)? Everything will be bought from Crutchfield.

By the way, I do have a changer that I can't wait to junk... Will just be using the head unit's dvd/cd player...

Thanks for any help offered.

Eric

[Jeron]

You can use a 4 channel amp. You need a two channels for the rear deck and you can use two channels for the front separates but you will need a passive crossover to go between each set of speakers so that each set of the front 6 gets only its correct band of frequency.

You can just use the headunit 4 channel output but you still need the crossover setup to run the 6 separated in the front.

A low cost option would be to replace four of the front speakers with a set of separates (two pairs) that come with a passive crossover. And drive rear pair and new front separates with the headunit. The remaining front pair would go unused.

Crutchfield.com is a good place to look at and I'm sure they will be very helpful.

[Eric-325I]

Thanks for the reply man...

So what your saying is that I can't just buy a 6 channel amp and simply swap it with BMW original one? Or does the BMW amp have the crossovers built in?

I could always just swap the stock unit with an aftermarket amp of the same number of channels and use in-line 'bass-blockers' of the correct type....

What do you think?

Thanks!

Eric

[Jeron]

Above I mentioned that you have 6 front speakers but I looked up your system in the Bentley and you have 4 fronts.

I don't know much about the factory amp but I would say it surely has crossovers built in.

You could buy a 6-channel amp with built in crossovers. (more Amp cost)
You could buy a 4 channel with crossover and a regular two channel for the back.
You could buy a 4 channel with a built in crossover and run the rear speakers from the headunit.

With a regular 4 channel amp running each corner:
You could use a bass blocker.
You could use a passive crossover.
You could buy a new set of separates for the front.

I can think of a few other configurations.

Until you are ready to replace the speakers I would just get a new headunit and a passive crossover, or blockers, to go between the front pairs and skip the amp entirely.