# HELP needed - speakers wiring



## WoRkZ (Sep 19, 2015)

Hello all! 

I am installing an after-market radio in my car in the place of the old Symphony unit. I managed to install it... but it sounds terrible. You see, the wiring harness that came with the installation kit sends the amplified outputs nowhere... and the only option I had was to hook the front RCA outs to a unique pair of RCA inputs on the wiring loom. From there, the front and rear RCA inputs for the car are soldered together so there is sound sent to the front and back speakers! The result is atrocious... and I don't have my fade control anymore (which I've always used to put the sound a bit more towards the back - personal taste).

Here is what I am working with here. As you can see, the amplified outputs to pins that have no equivalent on the OEM loom. Is there a way to then hook those up to the car's wiring so that I can have independent rear and front outputs? And is there an amp somewhere in the car? How else is the sound amplified from the RCA inputs to the speakers...

As you can see, the amplified channels coming from the head unit are not connecting to anything on the OEM loom.

View of the back of the car's connector (with after-market harness attached)









View of the front of the car's connector









Nothing on the new HU's wiring harness connects to that blue colored cable on the OEM side either.


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## TT'sRevenge (Feb 28, 2021)

Do you have the Bose system or no? Looking at your pictures of the car it doesn't look like it but I can't be sure.

Either way it seems the system you have is fully amplified meaning the speaker outputs of the Symphony II+ are not used in your configuration. The speaker wires are therefore going to come from the amp in the back which should be behind the left side trim in the hatch. You have one of two options:
1. Access the factory amp and identify all the speaker wires. Unplug the amp and cut/splice the wires going to the speakers with wires coming from your replacement HU's speaker outputs/amp.

2. Try to feed a line level signal to the amp (make sure you turn it on with +12v amp turn-on signal from your HU to the DSP EIN pin). The line level outputs are connected in the green connector in the quad-lock. Note there is a common ground pin for all signals.

If you try #2, be aware the line levels may vary from the factory HU to your replacement unit so it may not end up sounding loud enough, or it may sound too loud and be distorted, depending. Therefore#1 is a better option. I'm not 100% sure but pretty sure the factory amp is not bi-amping anything and the tweeters in the car probably have a simple cap-crossover on them, so you should only find four speaker wire pairs (+&-) at the amp. The pinout on the amp or the wire colours I'm not sure about but might be in the knowledge base or in another thread.

I'm not sure why/what you've soldered together though? I'm a bit confused on that.

For the amp location have a look at this thread:
https://www.ttforum.co.uk/forum/viewtop ... 9&t=111423


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## SwissJetPilot (Apr 27, 2014)

You might want to use the Forum search function and enter the brand and model of the head unit you're installing as it's possible someone has already done this before.

For wiring diagrams you can download the following workshop manuals from the _*Knowledge Base*_. You will find these are all under *Section 2* -

*FAQ - Audi TT (8J) Workshop Manuals & Self Study Programs*
https://www.ttforum.co.uk/forum/viewtop ... &t=1833829

*• Wiring Diagrams & Component Locations - A005TT20021
• Communications - RG 91 - D3E8006B7D9
• Bose Amp Technical Service Information
• SSP 382 Audi TT Coupé '07 - Electrical & Infotainment*

If your head unit doesn't provide an Quadlock adapter, rather than hacking into the existing wiring, you may want to look at sites like *Kufatec* or *Ampire* (both German) as they make various harnesses for aftermarket and retrofit projects. They may be able to provide you with a harness adapter that's plug-and-play.

https://www.kufatec.com/
https://www.ampire.de/?shop=ampire_en

As noted by *TT'sRevenge* if you have an amplifier it will be located behind the left rear trunk panel as shown here.

There is a way to code your sound system to change the characteristics of the system to improve the sound, but you'll need a OBD device like VCDS or OBDeleven to make the change.

*VCDS Module 47-Sound System*
https://www.ttforum.co.uk/forum/viewtop ... &t=1910619


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## tttony (Dec 21, 2014)

I assume that you have what Audi call the "Standard Sound System" rather that the "Basic Sound System" or the "Bose Sound System".

The Standard Sound System consists of nine speakers that are all driven by a five channel DSP amp in the boot. To drive the amp in the boot, the factory head unit, whichever one it is, outputs line level signals for right and left front and right and left rear. Those four signals together with a common earth/ground are on pins in the green connector in the cars quadlock connector. The speaker outputs on the bigger pins of the quadlock are not used.

You have not said what aftermarket HU you have fitted, but whatever it is, it has to provide the four separate line level signals mentioned above to power the cars amp in the boot.


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## tttony (Dec 21, 2014)

> Nothing on the new HU's wiring harness connects to that blue colored cable on the OEM side either.


The blue connector block in the cars quadlock connector has pins for the AUX in and CD player signals.

If your car has a factory fitted AUX in socket behind the handbrake lever then it will not work with your new HU unless you add the necessary pins and cables to the quadlock connector that came with your new HU. This assumes that your new HU has an AUX in socket on its back panel.


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## John949 (Apr 12, 2017)

Just to clarify what others have said.

The Audi system uses line inputs from the head unit to the amp, these are on the green connector. The speaker outputs are not used.

If your head unit does not have line outputs then the speaker outputs can be used via a line output convertor.

There are several threads on fitting aftermarket radios which will cover most of the issues if you do some research.

I think it's fair to say that fitting an aftermarket radio not designed for the TT is problematic for most people. The CAN based steering wheel controls can also be an issue. This is why most people opt for dedicated TT units like Xtrons.


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## WoRkZ (Sep 19, 2015)

Big thanks to all of you guys! You are awesome (as always)! 

I will try to remove the panel at the back of the car and confirm I do have an amp... but I don't see how I wouldn't have one.

To be clear, my new HU only provides line outputs for fronts speakers... but the harness the seller provided merges this into the front AND rear line inputs on the OEM harness!  As an IT tech, I know enough to know this is just terrible... and certainly why the quality of the sound is so poor. :roll:

I am quite curious about the line output converter. I didn't know this existed. I am also looking at an amp I would install behind the HU that would accept amplified inputs (if those still exist... they did in the past). I suppose there would then be a way to connect to the factory harness and route the amplified signal to the speakers. I will have a look at the documentation SwissJetPilot linked to in order to figure out that part. Fingers crossed there is a way to do that and avoid having to run tons of speaker wiring... :?

Oh, and the seller gave me the admin code for the unit... so I played with it a bit, got it to recognize my CANBUS adapter and all the steering wheel functions now work perfectly. 8)

Again, your help is quite welcome! Cheers guys!


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## WoRkZ (Sep 19, 2015)

UPDATE

So, this what things look like in the truck of the car right now. I don't see an amp. Instead, there's this weird connector that seems to send signal back to the front of the car... not sure what that's all about... :-|


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## FNChaos (Nov 30, 2016)

Not sure where exactly where in your truck your pictures are taken, but if you are showing the area left-side behind the back seat then it looks like the cabling for a Sirius satellite receiver

As both TT'sRevenge & SJP pointed out, the BOSE amp (if you have one) will be mounted on the 'hump' that makes up your left wheel well. You will need to remove the side panel and any insulation / noise reduction to access it.


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## WoRkZ (Sep 19, 2015)

FNChaos said:


> Not sure where exactly where in your truck your pictures are taken, but if you are showing the area left-side behind the back seat then it looks like the cabling for a Sirius satellite receiver
> 
> As both TT'sRevenge & SJP pointed out, the BOSE amp (if you have one) will be mounted on the 'hump' that makes up your left wheel well. You will need to remove the side panel and any insulation / noise reduction to access it.


Oh! That's not where I was looking at all! I looked where you showed the Sirius box... 

Okay, will have another look tomorrow then.


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## SwissJetPilot (Apr 27, 2014)

As my grandfather used to say, "If it were a snake, it would have bit you!"


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## WoRkZ (Sep 19, 2015)

SwissJetPilot said:


> As my grandfather used to say, "If it were a snake, it would have bit you!"


Wait, what is that? Because that is near the driver's side tail-light... :?:


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## SwissJetPilot (Apr 27, 2014)

WoRkZ said:


> ... that is near the driver's side tail-light...


If you're driving a left hand drive vehicle, that is correct!


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## tttony (Dec 21, 2014)

Just to make things clear for you WoRkZ, the amp for the "Standard Sound System" is located in the same place as the Bose amp.


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## TT'sRevenge (Feb 28, 2021)

WoRkZ said:


> Oh! That's not where I was looking at all! I looked where you showed the Sirius box...
> 
> Okay, will have another look tomorrow then.


Yeah you have to actually take apart the side of the hatch--there should be either articles in the knowledge base or details in the service manual section if you need help.

I'm surprised you don't have the Sirius tuner in a Canadian car, they were pretty much standard those years, due to the partnership (kickbacks? lol) with Sirius at the time. Actually I'm not sure if current cars still come with this but yeah a lot of cars just had em' in the late 00s/early 10s, pretty sure you still paid for it but there wasn't much choice as majority of cars on the stealer lots came with it.

I would imagine your vehicle might have been an ordered vehicle--i.e. something not on the lot at the time of purchase (not sure if you owned since new or bought used but whomever bought it originally probably ordered it).


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## WoRkZ (Sep 19, 2015)

So, I've decided to buy this 4 channels amp (with high-level inputs). I will use the amplified outputs from my new head unit and feed them to the amp. From there I hope to use the factory wiring to the speakers.

https://www.amazon.ca/dp/B004S50ZDA

Whish me luck!


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## tttony (Dec 21, 2014)

Why would you want to take out the 5 channel DSP amp of the "Standard Sound System" and replace it with a 4 channel amp?


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## FNChaos (Nov 30, 2016)

WoRkZ said:


> Whish me luck!


I wouldn't get my hopes up on that amplifier...

400W for $62.15CDN ? (Expect an amp with those power specs to run $250 - $400)
Weighs only 1.41 kg? (typical amp weighs between 2.5 - 7 kg due to transformers, heatsinks, etc)

Specification page is laughable, Freq response 12 Hz to 22 kHz ! with a THD of 0.010000000000000000208 % (wonder what tool they used to measure down to 10^(-19) :lol: )

Reviews are terrible and there is a no return policy? [smiley=thumbsdown.gif]


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## TT'sRevenge (Feb 28, 2021)

Yeah um hate to say it but that's an IC amp--says right in the item title. IC amp = same as head unit amp. Should probably return--easy enough through Amazon 



FNChaos said:


> Reviews are terrible and there is a no return policy? [smiley=thumbsdown.gif]


Nahh shipped & sold by Amazon, you might not be seeing them as the seller if not in Canada--return will be easy peasy.


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## FNChaos (Nov 30, 2016)

TT'sRevenge said:


> FNChaos said:
> 
> 
> > Reviews are terrible and there is a no return policy? [smiley=thumbsdown.gif]
> ...


Cut from linked page: 

*About this item*
400 W MAX Power, 4 Channel 75 W X 4 RMS @ 2 ohm 38 W X 4 RMS @ 4 ohm
Full Range, Class A/B,
High and Low Level Inputs
6 Year Platinum Dealer Warranty
100 Watt, 4-Channel
Remote Subwoofer Level Control
4-Channel
*This Item is NON Returnable*

[smiley=book2.gif] Several reviews also indicate this to be true...


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## TT'sRevenge (Feb 28, 2021)

FNChaos said:


> Cut from linked page:
> 
> *About this item*
> 400 W MAX Power, 4 Channel 75 W X 4 RMS @ 2 ohm 38 W X 4 RMS @ 4 ohm
> ...


Hmmm wow looks like you are right, I've never even seen that before on something like this. I mean I could imagine a toothbrush or something is non-returnable but this? Weird. However that is in the description and sometimes description stuff doesn't mean anything, so could always try... Or could notify them now before it arrives and say you made a mistake in ordering...

That's a lot of money for an IC amp too :|


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## WoRkZ (Sep 19, 2015)

Guys, I've had very expensive sound systems in my car... including an all Yamaha setup. But that's not what I am looking for here. I just want to connect my new head unit to the OEM speakers and have something that sounds like that very average Symphony radio I had. I ordered the cheapest amp I could find that had 4 channels and accepted high-level inputs. It would be extremely surprising I wouldn't be satisfied with such low expectations.

Don't get me wrong: I am somewhat of an audiophile. But I am very rarely in my car alone... and cars are noisy places that are not conducive to high-quality audio listening unless the volume is much higher than what I like anyway. So don't worry: As long as there's some sound coming out of the speakers and it's not distorted, it will be quite okay. I just need to figure out how to wire this in and I can move on to other much more interesting projects... like my new brake set (four corners), having my front grill repainted and stuff like that. 



tttony said:


> Why would you want to take out the 5 channel DSP amp of the "Standard Sound System" and replace it with a 4 channel amp?


I'm still unsure there's even an amp there... but in any case, it looks like it works through low-level inputs and my HU only has one RCA outputs pair (apart from the 4 channels amplified ones). So I am just improvising here to achieve something acceptable to me. Right now, it just sounds a bit too crappy for me. So I am sure once I can send sound to all speakers I will be okay leaving things like they are.


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## tttony (Dec 21, 2014)

> I'm still unsure there's even an amp there...


If you have a centre dash speaker (not just the grill) and speakers in the rear side panels, then you have an amp in the boot. See the attached picture for details of the "Standard Sound System".

All the connections to the amp in the boot are on a single multi-pin plug. To use your new amp with the car's existing speaker wiring, you will have to splice into the relevant wires as they leave the plug.

I fear that you will be removing the very adequate factory amp and replacing it with a probably less good one just to get around the fact that you bought a new HU which does not have the required line level outputs. If I were you I would return or sell the new HU and then buy another one that will utilise the car's existing sound system.


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## WoRkZ (Sep 19, 2015)

I did put a brake on things, cancelled my order for the amp... and will take time to figure things out. 

If the amp in the car is much better than any cheap amp, I could always use a high to low level converter for the back channels. Or as you said, maybe simply ditch the HU and go with another one... who knows. I'll think about it, figure out how to remove the trunk trim without damaging it, then go from there.


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## WoRkZ (Sep 19, 2015)

So, things are looking better as I work on this a bit more. This is the look it should have once everything is in place. 

(yes, I know, my car is filthy... it's not had its post-winter clean-up yet)

I need to make the unit fit flusher to the dashboard, GPS antenna is yet to be routed and I am still waiting for my FM antenna adapter. Also, I just placed an order for a NVME SSD enclosure that I will shove a 256GB M.2 drive in... and that will then contain most of my music collection.


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## Jezzie (May 24, 2020)

What happened to the airbag warning light?


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## WoRkZ (Sep 19, 2015)

Jezzie said:


> What happened to the airbag warning light?


I chugged it behind the HU :lol:

EDIT: There's no obligatory technical inspection here... ;+)


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