You're in trouble. (long instructions) (archive)

Unless I've figured it out wrong, the e32 system of old cars like yours use the "common ground" system where there are is just one wire per speaker leaving from the deck and the speakers are all grounded to the car body.

Since this system was lousy and not power-efficient, it was discontinued finally and in fact I know of NO modern decks that use common ground.

Any non-common ground decks will be damaged if you try to run them with the - (negative) leads of the speakers connected to the car body.

Adaptor would connect the factory amp to the speaker level outs on the new head unit.

Sounds too good to be true and most likely is.

The question is, WHY ON EARTH would you like to use the original THIRTEEN year old speakers that might have been pretty OK at that time but are really nothing compared to most systems on the market.

And WHY ON EARTH would you like to use the bulky feeble amp provided by BMW 13 years ago?

And WHY OH WHY would you use THIRTEEN year old speaker wiring when you are UPgrading your system?

Couldn't I just use the RCA pre outs on the new head unit to connect to the factory system?

No. There is no RCA on an old crappy amp like that.

You can:

a) replace the deck and run some new wiring to the original speakers (they're old and have small magnets and are therefore NOT capable of much bass but the clarity is almost acceptable) and disconnect the factory amp

b) replace the deck AND speakers and run some new wiring (did this one already myself, sounds great with a powerful deck) disconnecting the factory amp

c) replace the deck AND the speaker wiring AND the amp AND the speakers (for the perfect sound. Add a sub or two if you want more bass). You must run the deck plus and minus from the battery and the amp plus and minus from the battery to avoid whine in the sound.

Other things to remember:
- The BMW original power wires WILL give enough power to a CD player
- It would be a REAL good idea to put in ISO connectors to make it a real easy swap next time
- Original speakers suck, I got more magnet on my freaking tweeter now than the original woofer had
- The original antenna, while not being a superb one, is a good and working antenna even after 14 years of use as long as you remember to give it power (white cord)
- Do it real well once and you won't have to do it again (weld the connectors to wires, use golden connectors, use very thick hifi cables)

Feel free to email me on audio issues

Henkka
audiophile

Follow Ups:

Just a few sidenotes Odd-Jarle / 91 750iL 18:12 6/10/2001 (3)
- Mind you it's a 1988 plus ground and RCA stuff Henkka 750i 00:12 6/11/2001 (2)
  - Oh yeah crossover stuff Henkka 750i 00:16 6/11/2001 (1)
    - OJ: found the PERFECT subwoofers for e32 Henkka 750i 00:23 6/11/2001 (0)

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