You might have to be more of an expert to do
what you want.
The BMW crossovers are built into the BMW amp. Most likely you'll end up with an aftermarket amp without built in crossovers and will have to install those next to the amp somewhere. They usually are quite large. Running wiring really isn't too hard. I only use dash mounted tweeters and kickpanel speakers (I don't use the door speakers at all). My crossovers are mounted under the dash above the footwells.
Link to BMW Wiring Diagram for 1998 Z3M
Thanks - Good Advice and Info
I really appreciate the diagram. It will help a lot - if I ignore your wise counsel in the first post and decide to try it on my own.
I didn't mention that I bought a set of Alpine component speakers a while ago just for the 5 1/4"s for the footwells. Your message made me go back and look and, sure enough, the speakers came with a pair of 2-way crossovers and they are relatively small.
I see 2 reasons not to do it myself:
1.) getting the alpine tweeters installed in the doors replacing the 2 stock speakers there
2.) figuring out how to get the wiring from head unit to amp and back to speakers and making it look good without spending too much time on it.
If I do it will be a learning experience whether I complete it myself or have to ask a local shop to finish what or have to yell HELP and ask a local shop to complete it for me.
thanks again - Tom
Are you keeping the stock head unit?
If not it's all new cabling.
Tom M.<img src="http://members.roadfly.org/tom_m/high_voltage_sign_spinout_md_wht_17652.gif" height=120 width=120>
"All of us get lost in the darkness
Dreamers learn to steer by the stars
All of us do time in the gutter
Dreamers turn to look at the cars" - N. Peart
You don't have to run new speaker wire...
An expert named Bob Hazelwood who worked for a/d/s here in New England advised that using the speaker wire already installed was the smartest thing you could do (check the archives). I installed new speakers, and placed the crossovers on a piece of thin plywood on the mount where the old amp had been, and ran the OE speaker wire from the new crossovers to the individual speakers - it's worked great!
Center console is fine for the RCA's
The only thing to watch out for is the car's main power wire when running speaker wires (they run down the passenger side of the car). So, it's best to run the speaker wires down the driver's side. Since you're using the existing speaker wires, you don't need to worry about this.
There are two rubber grommets in the rear deck - one on each side of the car. The passenger side has the car's main power wires running through it. I would route any additional wiring through the driver's side grommet (to keep them away from the vehicle's power wires).
I believe there is a capacitor used as a filter in the door panel. I would bypass this if you're using the Alpine mid and tweeter combo with the Alpine crossover mounted in the trunk next to the amp.
Mounting the Alpine Tweeters?
I can't remember how the factory tweeters are mounted in the door - to the back of the door panel? Are they screwed in?
If I pull the factory tweeters to put in the Alpine tweeter - can I use either set of speaker wires inside the door panel?
Ron Stygar's Photos shows two separate pigtails
One for the tweeter and one for the mid. You just want to make sure there is no filter going to the new tweeter. If the mid wiring goes although way to the rear amp, you'll just not use those wires.
.com/forums/showpost.php?p=3845005&postcount=58]Ron Stygar's Door Removal Pics
Roadfly prohibits my link
Type in "erfest" in place of the asterisks above.
Learning lessons 'Long theWay
I'm a little confused and you seem to be one who can clear things up for me.
The Alpine amp has crossovers built in, right? Don't they split the signal the correct way?
So you're saying that I should have a full range signal come from Channels 1&2 and let the crossovers split it between the tweeters in the door and the mid-ranges in the footwell?
Then set channels 3 as you suggest, to get a full but not overpowering signal to the Blaus.
It sounds simple but I thought the amp would split the signal adequately.
Back to the trunk tomorrow.
Re: Learning lessons 'Long theWay
I agree with Mike about going through the Alpine crossovers, but have you thought about bridging the amp channels 3 and 4 to drive your sub and either forget about the 4" rear speakers (they're almost worthless any way) or if you have to have them drive them from the head unit.