Stereo install - No Mo Bose update

Ingo D. Rautenberg ingo at
Tue Dec 16 12:56:49 EST 2003

OK.  Mom's car is finally finished.  It took me a lot longer than I expected (don't these things always), but much of that time was spent analyzing what to do and in proper fashion.  Subject car had original Delta Bose system with only one properly functioning speaker/amp combo (left rear), but even that one was deficient in the Bass department -- and that's saying something.  While it may have been possible to reuse all the speaker drivers, I chose not to for a few reasons:

1.  The extremely low impedance of these speakers (like 0.7 ohms measured).  This compares with a range or between 3.3 and 3.5 ohms on aftermarket speakers (Pioneer and Polk tested).  Didn't feel like testing my amp to see if it would blow.

2.  These are full range speakers that don't even have a whizzer cone -- so definitely lacking in the higher frequencies.  The speakers themselves are super durable in construction -- it's the amps that fail.  Interesting tidbit:  The front speakers were very soft/ low volume.  This from a fully functional head unit that worked fine in another car.  The only functional rear speaker had a plug-in type amp -- the other rear (non-functional) had the soldered-in amp.

What I did (after removing door panels, door sills and trim pieces, rear seat bottom, all lower trim carpet,kick panel and trans tunnel carpeting, etc):

a. Removed all speakers (door enclosures and rear deck)

b. Removed Amp-turn on relay

c. Removed (unplugged) choke with attached capacitor supplying power to all amps

d. Cut wiring to door speakers just where loom enters door bellows and pulled through (after cutting speaker connectors) with new speaker wiring taped to old wires

e. Routed speaker wiring back to trunk along with one coax cable pair on each side of the car (one for front speakers, the other for rears).  Installed 4- channel 75w x 4 RMS Sony 475-GSX amp underneath rear parcel shelf.  This now discontinued amp can be used as a four channel (4 x 75), two channel (2 x 150) or three channel (2 x 75 + 1 x 150) for subwoofer installation.  Picked a couple up on Ebay.

f. Wired up amp with 8 gauge cable and fuse (sourced complete 4-channel 8 gauge amp install kit from Knukonceptz in Ohio at for $24 ea. plus shipping.  An unbelievable deal and quality product (no affiliation).

g. Using Dremel tool, smoothed out ridges so that aftermarket head unit cage and radio would fit.  Said head unit in this case was a Kenwood unit I purchased earlier this year for my previous Urq with MP3 capability and adjustable background and button colors (unfortunately silver face in this case).

10. Removed Bose speakers and amps from Bose door enclosures and installed Polk 4" two-way speakers after cutting the tabs a bit to fit, including the addition of some butyl for air-tight seal.  

Tested, reassembled and done!  Sounds great but this job is definitely not for the faint of heart.  I will most likely be doing it again on my V8 and can probably do it in 6-8 hrs instead of (Insert large number) hours.

If you've only got one bad amp or two and are planning on keeping your head unit, I'd very much consider either repairing or buying replacement amps.

After doing this job I understand why car stereo installation shops shy away from these things.

Happy listening...

'91 200q20v...Slightly modified
'84 Tornado Red Urquattro
'91 v8 quattro 5-Speed (not exactly stock) :-)

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