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Bose half amped or fully amped??

Discussion in 'In-Car Entertainment' started by kjc300, Jan 2, 2009.

  1. kjc300
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    kjc300 New Member

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    I have a '99 A3 1.8T with a concert stereo that says 'Bose' when the stereo comes on. I also have the sub and cd changer in the boot side panel.

    Now, I would like to change the factory concert unit as it has the volume knob problem, so I've been investigating what I need to do it.

    I got asked wether the bose was half amped or fully amped when enquiring about the leads I need to fit my bluetooth kenwood head unit. I have no idea!! lol. How can I check that?

    Also read I need an aerial adaptor? And obviously fascia adaptors (which are the best ones?)

    So can anyone take the time to do a shopping list for me please??

    Many Thanks in advance, Kev. :thumbsup:
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  2. AndyMac
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    AndyMac Moderator Staff Member Moderator

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    All Bose systems on the A3 are fully amped.
    You will probably get the infamous "popping" problem if you switch to an aftermarket HU and use the RCA input adapter to link to the Bose amp. You'd be far better off replacing the Concert with another Concert TBH. Aftermarket HU's don't work well with the Bose system.
    If you do go ahead then you'll need:
    http://www.caraudiodirect.co.uk/aerial-adaptor-p-211.html
    http://www.caraudiodirect.co.uk/audi-facia-adaptor-p-611.html
    or
    http://www.caraudiodirect.co.uk/facia-adaptor-p-4444.html
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  3. kjc300
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    kjc300 New Member

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    Hmm, cheers Andy.

    If I wanted to disregard the bose system and fit an aftermarket HU, what would I need to do?

    Are the power connections ISO? i.e. could I plug it straight in and just run new rear speaker cables or is there more to it?
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  4. AndyMac
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    AndyMac Moderator Staff Member Moderator

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    More to it I'm afraid, you'd be far better off with a non Bose system. The Bose sstem is fully amped and uses non standard 2 ohm speakers which you can't run off an aftermarket HU so you're stuck with using the Bose amp or ripping everything out. The power is ISO but the perm live and ignition on live are back to front so yu need to swap them over.
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  5. mephisto
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    mephisto Member

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    You will also need this wiring harness:

    http://caraudiosecurity.com/shop/product/products_id/1570.html

    PC9-410

    Plus the PC5-52 if you go, for the pionee HU's.



    Andy,

    i don't understand why this popping occurs, i had this on my pioneer head unit which i returned as i thought it was the head unit, well and because the thing blinkered like a fekin Xmas tree. (Pioneer DEH-P7000)
    What's our options, how many amps are there, im aware there's one in the sub. Is there another?

    cheers.
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  6. AndyMac
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    AndyMac Moderator Staff Member Moderator

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    Yes there's 2 amps on the Bose system.
    A 4 channel in the drivers side cubbyhole in the boot driving all the speakers and the other inside the tupperware sub just or the sub.
    The popping occurs because the Bose amp doesn't use standard signal input grounding to prevent electrically noisey operations like changing source or CD track being amped through the speakers. It uses a bizarre array of capacitors on the input stage instead. So when an aftermarket HU grounds the RCA signal when changing CD track it discharges these capacitors causing the popping. the only way round it is to either:
    1. Use the speaker level input adapter which uses a hi to lo converter (line out converter) to take the speaker outputs from your Pioneer back down to RCA pre-out level. This compromises the sound quality and can introduce hiss and whine as the signal is being amped twice.
    2. Solder a capacitor on the signal pin for all 4 channels as per the thread below. This isolates the grounding from the HU to the amp without compromising the sound to any noticeable degree.
    http://www.audi-sport.net/vb/showthread.php?t=26307
    3. Ditch the Bose amp and speakers.
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  7. fran-s3
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    fran-s3 Active Member

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    Andy's been a legend in helping me sort my issues. Just to add my experience, I managed to rid the popping issue by using two Ground Loop Isolators instead of having to solder a capicitor to the signal pin. I used these http://www.maplin.co.uk/Module.aspx?ModuleNo=33172 but I have a double din so plenty of room to hide them, the round magnet in the middle is bigger then you think so space to put them becomes an issue. You can do what my friend did as he had a single din and not enough room to put them, is to locate them behing the glovebox and just run the wires you need from it behind there.

    It worked perfectly for me, it may not for you - worth a punt though if your going down this route. I have a Alpine X001 headunit fitted and running through my Bose system.
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  8. mephisto
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    mephisto Member

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    Thanks Andy/Fran,

    thanks to both of you to take time to reply, i reckon im gonna go down the inline caps route, will post back my pics for other people to enjoy!

    cheers,

    M.
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