Re: E34 Audio (long)

[Bob Hazelwood <woodyh@xxxxxxxxxxxxx>]

Finally, a question I can answer. Not being an expert on light flashing, proper fog
light use, or the Lewinski blower, I was beginning to feel like I could not
contribute.

The E-34 (E36, E46, and E39 too for that matter) is actually a rather easy car to
upgrade once you realize the unusual design of the BMW system's architecture. Most
systems, including any aftermarket speakers you find, consider the speaker's
crossover as part of the speaker. BMW on the other hand, puts the crossover
components in the amplifier chassis. There is no place outside the BMW amp to get
the full-range signal that an aftermarket set of speakers requires to properly
operate. This essentially means that if you want to replace the speakers you will
need to replace the amplifier too. On the other hand, with the right amplifier
choice, it is possible to replace the amp without replacing the speakers if you are
so inclined. The best way to do this is with a multichannel amp which has a built-in
electronic crossover. It can get a little tricky to set-up, but it is possible if
you should want to keep the factory speakers. The up-side of BMW's architecture is
that you can use virtually all of the factory wiring, since the vehicle's stock
harness brings everything back to a convenient point in the trunk.

In an effort to keep this from being accused turning into thinly disguised spam, I
should let you know that I work for audio manufacturer a/d/s/, so you can factor
this obvious bias in to my comments.  I'll tell you what I did with my '93 525i, the
essentials of which you can apply to virtually any brand you choose that makes
similar equipment. I'll also try to refrain from using all caps and excess
punctuation so I retain some sense of credibility ;-).

The front three-way OEM system is a little strange. The "midrange" really does not
go any lower in frequency than most tweeters, so it seems that it is there more for
marketing than performance. Replacing the front system with a 5-1/4" two-way
component system is practical and effective.  I am using the a/d/s/ 335is system up
front with the woofers in the factory locations and the a/d/s/ tweeters in the
factory midrange locations. The higher capability woofers required a bit of
attention to keep the panels from rattling, but it's nothing that a little Dynamat
and foam couldn't take care of. If you are using a BMW phone with hands free,
replacing the front woofers means that you will need to supply an additional speaker
somewhere to restore the hands free speaker. BMW uses a dual voice coil woofer in
the left kick-panel with one voice coil for audio and the second for the phone.  For
the rear, a set of A5im 5-1/4" coax's work well enough in the factory plastic
housings. Since groceries and space for a baby carriage took priority over a
subwoofer enclosure I punched out the access panel for the ski-bag behind the
armrest, and installed an a/d/s/ 310rs 10" subwoofer in a wood panel made out of 1"
MDF firing through the armrest. I'm using a n a/d/s/ P840 8-channel amp to drive the
system, it is set up in 6-channel mode with 4-channels driving the main speakers and
the other four bridged to two, driving the dual voice-coil subwoofer. I have it
installed under the rear deck next to the CD changer so it's up and out of the way.
I kept the BMW radio and CD changer (Pioneer), and am using the factory wiring
harness for everything except the +12V power for the amp. This amp may even take
more power to run than an electric supercharger, so I figured the skinny cable BMW
provides for power was not adequate. Until you turn on the system, you'd never see
that there was anything other than factory audio installed. The Bentley manual has a
good wiring schematic for the two different wiring schemes used for E34 audio.
Ironically, I have had more success using the non-shielded BMW twisted-pair factory
wiring from the head unit to the amp location than with any aftermarket high-end RCA
cables as far as system noise is concerned. I guess the BMW engineers did their
homework better than either the ones who designed the M42 profile gasket or who
chose to put a rubber cam belt on an engine with no valve-to-piston clearance
(doh!).

Feel free to E-mail with any questions.

Bob Hazelwood
VP Product Management, a/d/s/
'93 525i, 5-sp, Sharked, BL/ss'd, H&R, Bilstein, etc.
BMW CCA (Boston)


>
>
> Date: Tue, 10 Nov 1998 16:28:13 -0800
> From: Phil Lane <phil_lane@domain.elided>
> Subject: E34 audio
>
> I'm looking for feedback from E34 owners (90 535i) on their
> selection of car audio over and above the factory audio.
>
> Here's what I'm looing to do:
>         1) upgrade speakers, but retain speaker placement
>         of factory speakers
>         2) upgrade receiver, looking for in-dash CD player 6 CDs
>         3) add amplifier and cross-over amp
>
> I want to keep the factory look and only upgrade what's behind the
> speaker grilles, any comments, observations, criticisms pls forward to
> phil_lane@domain.elided
> TIA
> Phil Lane
> BMW CCA GGC
> 90 535
> 70 02
>
>

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