1999 S3 Audio Problem With Aftermarket Stereo

hugepiece · 12-26-2006, 11:32 AM

I've just purchased a 1999 Audi S3 with the Bose option but no headunit attached. It already had the correct Bose converters fitted to allow me to use RCAs. I've just fitted a Kenwood mask unit. I'm using both RCA outputs for sound and not the speaker outputs at all. All is working except for 2 problems - Firstly i get a soft whine over the audio that gets louder as you accellerate but not to the point that you cannot hear properly. Secondly and probably worse, I get a loud popping noise from the speakers whenever I change sources or change radio channels etc. I've checked the loom and everything seems ok. Would appreciate any suggestions as this is driving me mad. Thanks.

randal · 12-28-2006, 07:11 AM

We're having the same thing here, except we're using a Pioneer HU with the proper wiring loom to convert the Audi wiring to the standard ISO setup.

It seems the whine only comes through the rear speakers (active, amplified) so I'm presuming the problem isn't with the HU as such - but more to do with the grounding on this amp. However, where it is I dunno!

There was also a spade plug brown terminal that went to the back of the original factory HU for grounding but I've tried connecting that too and I don't think it made the blindest bit of difference.

Anyone else had this problem when fitting an after market stereo in an A3/S3 with the Bose hook up?

Thanks in advance
randal

hugepiece · 12-28-2006, 10:55 AM

I've done some more research and apparantly it it the grounding for the amp, it is backwards polarity or something. I am told the solution is to use ground loop supressors between the RCA for the amp and the RCAs for the stereo, have ordered 2 from ebay so will let you know if it resolves the issue.

randal · 12-28-2006, 11:54 AM

ahhh good old ebay.

I've not actually found where the factory amp sits, so not sure of the following - but is it driven by RCA input then? Because the leads on the back of the HU look far too thin to go into RCA.

Or are you talking about aftermarket amp etc..?

Cheers

hugepiece · 12-28-2006, 05:17 PM

if you look in the boot there are two compartments at the sides, the one on the left has the sub box and the one on the right has the bose amp. Basically the autoleads converter takes the preouts (standard cable) and gives you two pairs of RCAs - one for front and one for rear and then a remote power cable, this powers up the amp. This would explain why you are not getting any sound from the back. It will also sound really poor, once you get the correct connections you would not believe the difference in sound. If you cannot find what I mean let me know and i'll take some photos for you.

hugepiece · 12-30-2006, 05:33 AM

ok, installed the ground loop isolators today and hey presto - problem solved....

HeySteve · 01-11-2007, 03:12 PM

im having a similar problem with my A3, i recently got a pioneer stereo installed and its fine with the front speakers but as soon as you connect the rear ones there is a hissing noise. It doesnt really bother me to much as i turn the music above the level of the noise but i would like to get it fixed.

hugepiece can you post a link to what you got off ebay as i get easily confused when it comes to audio stuff.

hugepiece · 01-11-2007, 04:35 PM

sure, have a look at item 270075509083. I bought 2 of these as my stereo has two pre-outs.

HeySteve · 01-29-2007, 12:39 PM

do you have any photo's mate, as ive having trouble putting this all together

12-26-2006, 11:32 AM	#1 (permalink)
hugepiece Newbie Join Date: Dec 2006 Location: London, UK Posts: 10 Gallery: (0)	1999 S3 Audio Problem With Aftermarket Stereo I've just purchased a 1999 Audi S3 with the Bose option but no headunit attached. It already had the correct Bose converters fitted to allow me to use RCAs. I've just fitted a Kenwood mask unit. I'm using both RCA outputs for sound and not the speaker outputs at all. All is working except for 2 problems - Firstly i get a soft whine over the audio that gets louder as you accellerate but not to the point that you cannot hear properly. Secondly and probably worse, I get a loud popping noise from the speakers whenever I change sources or change radio channels etc. I've checked the loom and everything seems ok. Would appreciate any suggestions as this is driving me mad. Thanks.

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12-28-2006, 07:11 AM	#2 (permalink)
randal Newbie Join Date: Dec 2006 Posts: 3 Gallery: (0)	We're having the same thing here, except we're using a Pioneer HU with the proper wiring loom to convert the Audi wiring to the standard ISO setup. It seems the whine only comes through the rear speakers (active, amplified) so I'm presuming the problem isn't with the HU as such - but more to do with the grounding on this amp. However, where it is I dunno! There was also a spade plug brown terminal that went to the back of the original factory HU for grounding but I've tried connecting that too and I don't think it made the blindest bit of difference. Anyone else had this problem when fitting an after market stereo in an A3/S3 with the Bose hook up? Thanks in advance randal

12-28-2006, 10:55 AM	#3 (permalink)
hugepiece Newbie Join Date: Dec 2006 Location: London, UK Posts: 10 Gallery: (0)	I've done some more research and apparantly it it the grounding for the amp, it is backwards polarity or something. I am told the solution is to use ground loop supressors between the RCA for the amp and the RCAs for the stereo, have ordered 2 from ebay so will let you know if it resolves the issue.

12-28-2006, 11:54 AM	#4 (permalink)
randal Newbie Join Date: Dec 2006 Posts: 3 Gallery: (0)	ahhh good old ebay. I've not actually found where the factory amp sits, so not sure of the following - but is it driven by RCA input then? Because the leads on the back of the HU look far too thin to go into RCA. Or are you talking about aftermarket amp etc..? Cheers

12-28-2006, 05:17 PM	#5 (permalink)
hugepiece Newbie Join Date: Dec 2006 Location: London, UK Posts: 10 Gallery: (0)	if you look in the boot there are two compartments at the sides, the one on the left has the sub box and the one on the right has the bose amp. Basically the autoleads converter takes the preouts (standard cable) and gives you two pairs of RCAs - one for front and one for rear and then a remote power cable, this powers up the amp. This would explain why you are not getting any sound from the back. It will also sound really poor, once you get the correct connections you would not believe the difference in sound. If you cannot find what I mean let me know and i'll take some photos for you.

12-30-2006, 05:33 AM	#6 (permalink)
hugepiece Newbie Join Date: Dec 2006 Location: London, UK Posts: 10 Gallery: (0)	ok, installed the ground loop isolators today and hey presto - problem solved....

01-11-2007, 03:12 PM	#7 (permalink)
HeySteve Newbie Join Date: Nov 2006 Location: Gloucester - U.K Posts: 12 Gallery: (0)	im having a similar problem with my A3, i recently got a pioneer stereo installed and its fine with the front speakers but as soon as you connect the rear ones there is a hissing noise. It doesnt really bother me to much as i turn the music above the level of the noise but i would like to get it fixed. hugepiece can you post a link to what you got off ebay as i get easily confused when it comes to audio stuff.

01-11-2007, 04:35 PM	#8 (permalink)
hugepiece Newbie Join Date: Dec 2006 Location: London, UK Posts: 10 Gallery: (0)	sure, have a look at item 270075509083. I bought 2 of these as my stereo has two pre-outs.

01-29-2007, 12:39 PM	#9 (permalink)
HeySteve Newbie Join Date: Nov 2006 Location: Gloucester - U.K Posts: 12 Gallery: (0)	do you have any photo's mate, as ive having trouble putting this all together

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