Wiring Amplifier to Symphony HU ?

[rasA4]

i have now bought a KENWOOD Subwoofer amp for my sub, but a bit confused on how to connect the amp to the Symphony HU at present i have 2 speakers in the front door cards 2 speakers in the rear door card and 2 in the parcel shelf i did buy a lead a while ago that looks like this

but when i tried to connect this lead to the HU i had to remove another plug

one of these

any ideas??

 

[AndyMac]

Yes unfortunately you have the single plug version on the Audi loom (some of them are multi part so you can slide on the adapter and not lose the other connections.
So basically the top black connector feeds the rear pre-outs to the rear amp, provides the feed for a CD changer if you have one and also the link to the DIS.
If you plug in just the yellow adapter you'll lose the feed to the rear amp, CD changer and DIS. If all you're doing is adding a sub & amp then you'd be far better off leaving the HU end alone and tapping the rear pre-outs and remote on at the rear amp already in the boot. Just cut off the end of an RCA cable and solder it onto the pre-out leads on the amp.

 

[rasA4]

thanks again Andy
damn! can i try and cut(split) the connector? has this been done before or is really not worth it?
if not is there a wiring diagram to the little amp in the boot to per out the sump amp
will i still have to run the remote lead o the HU or is there a remote on the little amp at the back?
are you going to the herts meet this sunday? thats if you live nearby

also had a look at running the power lead to the battery i opened the ECU box(i think) is it the one in the engine bay near the wipers end drivers side, i had a look inside i couldnt see how on earth im going to run the power lead from inside the car


cheers

 

[rasA4]

also just to add i have a phatbox box as well so i dont think cutting the plug is gonna work.. i was running the rear speaker wires to the rear doors today what a job taking of the plastic trims i had to take off soooo much of it just to run cables AND putting it all back was a nightmare!!! my back is hurting and all my fingers are as well .....

 

[2003 a4 sport tdi 130]

hi guys... how hard is it to run wires through a b6 a4 sport???? anyone here changed a headunit???? where can i get the fascia adaptor from???? will my bose amps still be running with the new sony hu??????

please help

 

[AndyMac]

If you need the changer part of that connector then I wouldn't try cutting it in two, much easier to tap the line-outs and remote on at the amp.
I take it you have the non Bose setup, so the amp is bolted to the rear speaker. So cut of one end of a pair of RCA's, strip them back, connect the screens together and you'll then have 3 leads (bare screen, red & white signal leads). You'll also need a blue remote on lead. Unplug the lead going into the left speaker and use some piggyback connectors to make the connections (or better still cut the wires you need and use a terminal block to reconnect them and pair them up with the RCA lead). Piggybacks are not the most reliable method.
Connect your blue remote on to the white wire.
Connect the RCA screen to the brown wire with red stripe (check this is 12v and switched on/off with the HU)
Connect the RCA white wire to the blue wire with green stripe.
Connect the RCA red wire to the blue wire with red stripe.

Hopefully these colour codings are the same in your A4, Audi are renowned for changing them on a weekly basis. As long as you get the remote on wire correct and you steer clear of the permanent live on the amp you can't really do much damage.

 

[rasA4]

thanks m8

also had a look at running the power lead to the battery i opened the ECU box(i think) is it the one in the engine bay near the wipers end drivers side, i had a look inside i couldnt see how on earth im going to run the power lead from inside the car?

 

[AndyMac]

You need to prise up the lid and right at the back behind the ECU is a big hole into the drivers footwell. Remove the trim under the steering wheel and shine a torch up, then you'll see it from the engine bay. Run the cable down into the footwell, don't try to run it up into the ECU.

 

[rasA4]

EXCELLENT

 

[rasA4]

Well managed to start looking at wiring to the audi amp i needed to fold the rear seats down and gentley pull up the rear parcel shelf it has the clips near the seats then disconnect the rear brake light. then it slid out quite easily after that. the speaker is secured by two screws.

here are some pics for anyone who wants a closer look at the speaker and the amp.

what a funny square shape speaker...

but wow its got a tweeter...

the mega amp!!

another view...

 

[AndyMac]

It's quality that only those pioneers in car audio, Nokia, could achieve!

 

[rasA4]

also the way audi made this design makes it difficult to replace these!

AndyMac did you use a standard terminal bloc to connect your sub amp to the multiconnector? ive stripped back the black cloth tape about 8 cm just wondering how you have joined the additional wiring?

 

[AndyMac]

I didn't cut anthing, just used some really small spade terminals (had to file them down a bit as well) with some heatshrink to insulate them so I could plug into the actual connector itself

 

[rasA4]

dont suppose you got any pics of this? or do you mean you are not using the small amp?

 

[AndyMac]

No not using the small amp.

 

[rasA4]

will i have any problems using the small amp with my sub amp?
im trying to find a neat way to do this instead of a bulky terminal blocs

cheers

 

[AndyMac]

No problems, I do it all the time on my A3/S3 sub installs. Could you not take the feed after the connector i.e. solder the RCA's onto the PCB on the tiny amp and leave the wiring and connector untouched? This is probably what I'd do, much neater.

 

[rasA4]

No problems, I do it all the time on my A3/S3 sub installs. Could you not take the feed after the connector i.e. solder the RCA's onto the PCB on the tiny amp and leave the wiring and connector untouched? This is probably what I'd do, much neater.

Hi Andy
i was all ready to solder the RCA cable to the PCB of the amp, and the it looks like i dont have enough room to solder onto it. Looks like ill have to dare i say it scotch lock onto the cable before the amp

oh by the way i routed the power cable the way you said thanks! easy when you know how

 

[AndyMac]

Sorry didn't know you were waiting for an answer. Yes you can use scotchloks you just need to ensure good contact. I normally slice the insulation to ensure the piggyback makes contact.
If you remove the pcb from the heatsink you can also get to the pcb and/or the back of the connector.

 

[rasA4]

If you remove the pcb from the heatsink you can also get to the pcb and/or the back of the connector.

i did andy the solder pins looked too close together m8

 

[AndyMac]

You'd be alright, you only need 4 of them

 

[rasA4]

well finally got round to FINALLY install the amp and it works! boy its powerfull i might need a better sub. i got a kenwood amp with a wired remote, however this only controls the gain and frequency responce which is still good as some tracks need more than others.

Is there anyway i can switch somewhere in the car so i can turn off the amp when the children are in the car?

 

[SamDude]

Wire a switch on the ingition wire to the amp so you can override it getting the 'turn-on' signal.

 

[AndyMac]

What he said.
Just wire the remote on to a switch under the dash somewhere

 

[rasA4]

thanks guys so i could just wire a switch in between the amp and the remote on lead in the boot to save ripping out the trim again?

also what switch do i need?


thanks

 

[SamDude]

See this one at: Maplins

or this: three-way throw (which I use as a toggle between:
Left - Amp On
Middle - All off
Right - Car PC on (which then triggers the Amp)

This lets me trigger the Car PC on or off as well as the amp without the PC running...

:icon_thumright:

 

[rasA4]

Amp installed however im getting a humming type of noise and it humms higher when i rev the car even if the HU is on with no volume what could this be?
ive run a earth from the amp to the under metal side of the parcel shelf.

 

[AndyMac]

Is it humming with the engine off?
Or is it just alternator whine?
Is it through the rear speakers or just the sub?
It's almost bound to be a ground loop of some sort.
Doubt the rear parcel shelf is a particularly good earth point so I'd try somewhere else closer to the chassis of the car. Failing that buy a ground loop isolator. Loads of people seem to get these interference issues, and I've never had it in 20 or so installs. Sure it must be linked to the quality of the amp in most cases. Alpine V12's just never seem to suffer from it.

 

[SamDude]

What Andy said.

Again, Maplin does/did a ground loop isolator for about £10 (about a year ago at least...)

 

[rasA4]

Is it humming with the engine off?

no it isnt m8 can this still be an earthing problem?

 

[AndyMac]

Yes, pretty much everytime. Try also earthing the chassis of the HU, the Audi earth is crap.

 

[rasA4]

thanks ill have to buy another length of earth wire now...
also its only coming from the sub

 

[AndyMac]

you're getting alternator whine from the sub?
That's almost impossible. Are you sure you have the amp switched to low pass? As the sub/amp combo shouldn't be able to recreate the frequency needed for alternator whine as it's only handling frequencies below 80-90Hz.
You still shouldn't be getting interference though
Make sure the earth lead is chunky and as short as possible.

 

[rasA4]

you're getting alternator whine from the sub?
That's almost impossible. Are you sure you have the amp switched to low pass? As the sub/amp combo shouldn't be able to recreate the frequency needed for alternator whine as it's only handling frequencies below 80-90Hz.
You still shouldn't be getting interference though
Make sure the earth lead is chunky and as short as possible.

luckly i used the the same earth cable and earthed it to one of the hooks for the luggage net and guess what... its still there
i wouldnt say it was a whine more like a rumble only when engine is running could it be the settings? as they are quite a few behind a panel on the amp its a Kenny KAC 8152.

 

[AndyMac]

You installed a sub amp & didn't adjust any of the settings?
Sounds like one of the pre-out screens is floating or something wierd like that. Have you tried disconnecting the pre-outs one at a time to see if the noise follows one or the other?

 

[rasA4]

You installed a sub amp & didn't adjust any of the settings?
Sounds like one of the pre-out screens is floating or something wierd like that. Have you tried disconnecting the pre-outs one at a time to see if the noise follows one or the other?

yea silly me also it was covered up by a metal plate and i could find the correct key to take it off. and i found that the gain was on 1 5 being min and 0.3 max if i remember rightly. and the freq was 200 i think. so ive turned them both down and the noise has almost dissapeared now.