Re: 98 5Series Audio Upgrade? (long) (archive)

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Good equipment choice ;-)
Installing the equipment you have is actually pretty simple. Your dealer is probably getting confused by the two-chassis radio in the front. The thing in the dash is just a display/control panel. The radio is a "black box" mounted out of sight. That's where the tuner and preamp circuitry is located. The amplifier is in the trunk behind the CD changer.
First, In an E39, E38, and E46, don't even think about replacing the head unit! Unless you have just won Powerball, it's not worth it. It will be an improvement, but it will be a small one and not worth the time and effort. The actual radio/cd electronics in the factory system are suprisingly good. It's just that you can't tell that through the factory amp and speakers. Have your dealer ignore everything electronic forward of the back seat, and simply pull out the factory amp behind the CD player. Everything they will need to connect the new system will be right there.
You have four channels of signal from the radio, 6 pairs of speaker wires from the front system (2 woofers, 2 midranges, 2 tweeters), 4 pairs of wires from the rear (2 woofers, 2 tweeters), remote turn-on wire (white), power, and ground. The only wire that should not be used is the power wire, because it is too small for the new amp you have. (The ground is kind of small too, but it is a short run so the resistance is much less than on the power wire. It won't hurt to run a new one, but it's not absolutely necessary.) Fortunately, running a new power wire is really easy with the battery in the trunk.
Connecting the P840 then becomes a simple matter of removing the proprietary BMW plugs from the harness, and replacing them with appropriate connectors to mate with the P840. In order to facilitate easy replacement of the BMW system in my own car (E34), I cut the BMW harness back 6" from the factory connecors. Then, I purchased Molex "Mini-Fit Jr." series connectors from Digi Key Electronics (http://www.digikey.com). I installed these connectors on the BMW harness, and their mates on the part I cut off. This way I can just plug it back together when I'm ready to put the car to pasture. Then I made another set of cables with the Molex connectors on one end and connectors on the other end to mate with the amps/crossovers. I used a 12-pin connector for the front speaker wires, an 8-pin for the rear speakers, and a 10-pin connector for the signal from the radio, ground, and remote turn-on. You could probably put these all on one connector, but I like to separate them by function since I do a lot of experimenting.
The four radio signal leads should ultimately terminate in RCA plugs and connect directly to the P840 inputs. The speaker leads will connect to the outputs of the respective a/d/s/ crossovers, and the only "new" wiring will be from the P840 speaker outputs to the inputs of the a/d/s/ crossovers. This will be standard speaker wire. I wish I could help you out with the color code, but I've been unable to get my hands on E39 documentation so far.
The speaker installation is pretty easy for any installer worth paying, There will be a little "futzing" to get everything sealed and solid, but no more than any other car, so this should not throw anybody for a loop.
Do NOT let your installer run new wires up front for the signal from the radio. You WILL get alternator noise! There is NOTHING better than twisted pair wiring for running low-level signal in a noisy environment, and that's what BMW already uses! Don't fall for the marketing hype of expensive audio cables. This is not home audio, the priorities are different. (Guess I better put my flame suit on now) Speaking of flames, pay for good wire, fuse block, and connectors for the power wiring though. It's a safety issue.
Subwoofers can take a lot of forms, depending on what you are after. In the DSP system, BMW cuts a couple of 3" holes in the rear deck for a bandpass enclosure. You can also cut through the center of the rear seat area (where the ski-bag option goes), for a 10" or 12" driver. This could be in an enclosure or infinite baffle. You can also get pretty good results without cutting anything if the subwoofer is powerful enough, but it's better to cut. The Ski bag area is not really structurally significant, early 5's had a punch-out panel there. It's basically left in place for noise reduction. (I wouldn't go overboard with the cutting though!)

Best regards,
Bob Hazelwood
VP Product Management, a/d/s/
'93 525i 5-sp. Sharked, BL/ss'd, H&R + Bilsteins
BMW CCA (Boston)
http://www.adst.com

: I have a 98 528i Sport Package with non premium sound system. And I was planning to upgrade my stock audio system. I went to couple of audio dealers around my town, however, I didn't get any clear answer from any of them. Because new 5 series has longer face unit, it is difficult to install with din size face unit. And also, if I stick with factory face unit, it is also difficult to upgrade amp and subs. Because, bmw audio uses factory amp as a tuner. I already bought A/D/S/ 335is 336is speakers and P840 amp. I also wanted to get subs and new face unit for my car. I will be appreciated if anyone tell me how to upgrade my lousy stock audio system.

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