Stereo Question.........

Hey ppl
First, the car this is going in.... 97 A4 1.8T with sport package and premium sound (though I dont think its bose - no logos anywhere on the casette deck or speakers etc....) I believe
the rear speakers are amplified by some crappy Nokia amps sitting under the speakers...
now on with the story...
alrite, after much trouble with a crappy install by professionals at a local store, I got fed up and returned their POS back to them coz they were never able to get it working properly.
So, I purchased an Alpine 9807 deck and I am going to install it myself... I also bought the AUDI wiring harness consisting of 3 connectors - A (8 pin), B(8pin) and C (three rows, 20 pins) to plug directly into the factory harnesses
So far, so good. Now the confusing bits... on connector B (which has all speaker connections), I can see only 4 terminals - FRT RR and FRT LFT + and -.
Now for the Rears, I see on block C1 (pins 1 to 6) pin 1 is line out RR LFT (pin1) and RR RGT (pin 2) but just one Line out ground (pin 3)
The replacement deck which I purchased has both + and - outputs for all four speakers...
I realize that I can't simply add those two -ve leads for the rr together.... as the new unit outputs a "floating ground" signal...meaning its not a constant ground
Now, whats the best way to do this? Should I just screw it and unplug the factory amps and speakers and run new wires just to the speakers?
Howcome the frt speakers are not amplified?
thanks.... I realize that this post will prob result in 10,000 replies about how I should do more research etc etc and its all been asked and answered before...anyway I have been trying to find specific info but no luck other than an audi world article which was a little confusing...all I am saying is, if you can help, please be my guest...otherwise dont waste your time and mine
thankss :)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
many car radios nowadays employ this system where only the rears are amplified, but this is usually where you use the line-out jack plugs to the rears via an amplifier, if you are just using the radios built in amp (ie: using all 4 wires for front and rear) then the output for all 4 speakers will be the same. amplifiing the rears only makes sence for the driver since you are much further away from the rears (in most cars anyhow) and also this allows you to add a subwoofer from an external amp in the rear of the car which isnt affected by the front speakers. once its set up you can adjust the fader to suit your ears etc. unless you want to use your existing cars amplifier personally i would rewire the speakers as you mention using (better quality) cables running seperate wires to each 4 speakers. the output from your new alpine wont really require an external amplifier anyway.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.