A3 8l non-Bose system issue with speakers?...

pangsterA3

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I've just taken delivery of my new head unit and set about installing it today - overall very happy with it:

http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/134427-first-mods-car-stereo.html#post1391738

The only issue I have is that I can't get the rear sub/speakers to work. From what I've managed to read on here I was able to establish I had the non-Bose set up (my stock set up consisted of a Concert I tape heaudnit, CD multi changer in the boot and the non-Bose subwoofer) so I bought the following wiring harnesses:

Autoleads PC9-404 (Audi to RCA leads)
Autoleads PC5-52 (Aerial adaptor)

The following is a picture of the harnesses/connectors in my car:

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As far as I can tell I've connected them all correctly? - some of the things I noticed were that stock head unit had a small brown spade connector (ground for something?) - which I transferred over onto the chassis of the new head unit. I also have one red connector with one wire left in it which isn't connected to anything?? (is this correct??)

I connected the switched/amp signal from the aerial amplifier to the the blue amp signal wire from the pre-out harness and then connected both of these wires to the remote cable from the head unit harness (the below picture was taken pre-connection! LOL!):

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But when I switch the head unit on - the fronts work but all I can hear from the rear is a static/buzzing noise - when I fade to rear - I hear nothing from the front and just this noise?.. I've disconnected the rears just now - but would like to get to the bottom of this if anyone can help offer any advice??
 
That all looks spot on, are you sure the rears/sub worked before you swapped the HU?
The amp is switching on otherwise you wouldn't even get static, maybe worth trying the PC9-404 plugged into the front pre-outs or the sub pre-out just to check it's the same on all channels as it could be a duff kenwood.
 
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That all looks spot on, are you sure the rears/sub worked before you swapped the HU?
The amp is switching on otherwise you wouldn't even get static, maybe worth trying the PC9-404 plugged into the front pre-outs or the sub pre-out just to check it's the same on all channels as it could be a duff kenwood.

Hi Andy

I was pretty sure the wiring was good as I read your previous posts.. There doesn't seem to be any change regardless of what pre out is attached.. The only difference is when the remote wire is disconnected.. The sub and rears worked before.. I'm a little stumped by this one..
 
not had much chance to try and get to the bottom of this today.. have had a bit of a play with the new head unit and can see several different options which may/may not help this issue (i.e. there's an option to switch the stereo amp on or off and various other filter options etc) - I'll also pull the unit and check the wiring over again.. although pretty sure this is fine as the amplified aerial seems to work well (the radio reception is spot on and the amp signal wire is hooked into the same place.. )

Is there any other fuses or relays that the subwoofer/amp/rear speakers hook into that could be causing the issue? - eventually I'll be replacing the speakers anyway - but until I get round to this I would at least like the factory ones to be working first..
 
Is there any music coming from the rears, or is it just static?
If you have a multimeter check the continuity on the PC9-404 adapter as it sounds like the screens are shorting to the signal. With the meter set on ohms check you have an open circuit on the RCA sockets between the core and the shroud (the inner bit and the outer bit). If there is any kind of reading between these then the adapter is faulty. Then check you have full continuity from the pins on the red part to the relevant parts of the RCA sockets i.e. LR to left RCA signal (core), RR to right RCA signal (core), and then screen to screen. All these connections should read zero ohms. If the rear/sub amp works with the stock HU, and all connections are correct then it sounds like you have a duff adapter. Can't think of anything else it could be.
 
Is there any music coming from the rears, or is it just static?
If you have a multimeter check the continuity on the PC9-404 adapter as it sounds like the screens are shorting to the signal. With the meter set on ohms check you have an open circuit on the RCA sockets between the core and the shroud (the inner bit and the outer bit). If there is any kind of reading between these then the adapter is faulty. Then check you have full continuity from the pins on the red part to the relevant parts of the RCA sockets i.e. LR to left RCA signal (core), RR to right RCA signal (core), and then screen to screen. All these connections should read zero ohms. If the rear/sub amp works with the stock HU, and all connections are correct then it sounds like you have a duff adapter. Can't think of anything else it could be.

it's just a static like noise.. I think you might be correct about it maybe being a duff adaptor..

Interestingly enough - when I turn the in built amp off - then no sound comes from the front speakers either.. (it says in the manual to turn this off to improve sound quality to the pre-outs?)..

I'll pull the head unit out and have a check this weekend.. :)
 
AndyMac: I forgot to say that I've just bought a set of your adaptor rings for the front speakers.. looking at component speakers for the front at the minute (if I've read correct then with these adaptors - I'll be able to fit 5.2.5" components in the front instead of the factory 4" - as long as they're not deeper than 54mm?)...

Once I get the rear issue sorted out then I'll also get round to swapping out the rears (with the aid of your adaptors! :) )

BTW the link to the instructions for fitting the front speaker rings (in the eBay advert) seems to be corrupt as the pictures are ok - but all of the characters show '?'
 
You can go up to about 60mm depth, but depends on magnet size.
PDF link works fine for me.
 
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Decided to go for some Pioneer TS-A131Ci for the front - specs below:

tsa131ci.jpg


Pioneer TS-A131Ci Features/Specifications:
  • Maximum output power 300 Watt
  • Nominal output power 35 Watt
  • Impedance 4ohms
  • Frequency response 28 - 29,000 Hz Hz
  • Sensitivity (1W/1m) 89 dB
  • Woofer size (cm) 13 cm
  • Woofer material Carbon Graphite IMPP Interlaced Aramid Fiber Cone
  • Tweeter size (mm) 20,0 mm
  • Cut-out Hole 121 mm
  • Mounting Depth 52 mm
Hopefully these will fit without too much hassle and as I'll be driving them direct from the head unit - figured they were a good match.. I was going to get the Infinity REF5030CS for around the same price - but there was 2 things that put me off.. the first were the impedance of them (2 Ohm) - my head unit, like most other aftermarket units is 4-8 Ohm and the mounting depth issue.. the Pioneers are 52mm, whereas the Infinity are 57mm...

I'm not looking to spend thousands on the stereo/speaker upgrade - but do want it sounding decent. I think I'll get the new speakers fitted in the front and see how they work out, look into getting the rears working and then decide what I'm going to do about upgrades for the rear. I was thinking about an AMSS and some Pioneer coaxials at some point.. see how this all pans out first though! LOL! :)
 
did you ever get to the bottom of this problem i have the same one at the moment and its so anoying
 
Yes turning off the internal amp on the Kenwood won't make any difference to the rear RCA's, it just improves the quality of the signal for a fully amped system as power is not being used at the HU to operate the internal amp.
Rewiring the rears directly to the new HU is a far better solution anyway as you have twice the power available at the HU and still only a puny 2 x 20w from the Nokia amp in the rear.