Re: Standard E39 Sound syetem (archive)

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Fortunately, the standard system is pretty straight-forward. There are four channels of common ground signal from the radio running through twisted pair wiring back to the amp location behind the CD changer. Then, a set of wires from each individual speaker location comes right back to the same place. You could not ask for a more upgrade-friendly set up!
An unusual but effective way to upgrade the midrange is to add a subwoofer.
Huh?
That's right, a subwoofer! It is not uncommon for the muddy effect to be generated by the same small 5-1/4" speaker moving so far trying to generate bass that the cone is distorting everything else too. By adding even a small subwoofer, and simultaneously taking appropriate measures to block the bass from the main speakers (200uF bi-polar capacitors in series with each 5-1/4" speaker), the midrange will clean up rather nicely. Knocking only one octave off of the low end of the midrange speakers will reduce 75% of the cone motion. This is what we call the "level 1" upgrade on our web site.
If this is not enough, the next step is to upgrade power and/or speakers. This can be done to all, or selectively. My value oriented suggestion is to upgrade the front system and leave the rear. That is unless you are chauffer driven, then do the reverse;-)
The nice thing about the BMW architecture is that all the necessary system connections are accessable in one place. The radio/CD is pretty good, and the signal levels present from the radio will plug right into an aftermarket amplifier without requiring line output converters or any similar band-aids. You will need to change the plugs from BMW's proprietary connectors to RCA jacks, but that is relatively trivial.
We'll have all the standard system wiring color codes up on our web site in a few days.

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

: Now if someone will just do the same for the non premium system (Mysteries of the "premium" DSP / AMP) - I will be forever grateful. I have fairly severe high frequency hearing loss (no, not rock music, just some big guns, mostly 5" :-) )and would like to clean up the mid range - it sure sounds a bit "muddy" to me.

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