Audi A3 8P Aftermarket Android Problems.

splinter-cell

Registered User
Ground should be black. If that doesn’t run into your car harness then that could be the issue.

Yes it is the black one. I have a few wires coming from the stereo side of the harness and just have a plastic cap on the end but aren’t connected anywhere else. They are labelled ACC, ILL and GND (black ground). My harness has a CANBUS adapter so obviously I have no need for the ACC and the ILL wires.

I guess maybe you’re right and this is the cause of the issue. Would it better to run this wire into the factory quad lock harness or extend it and ground it on the metal behind the dash?
 

silverpiston

Registered User
Hello friends,

I have also some buzzing from alternator.
Splinter-cell, did you find a way to end this buzzing ? I also have a bose amplifier.
 

silverpiston

Registered User
Hi everyone,

I've got some news to fix a bit the problem. I've installed two ground loop isolators PAC SNI-35.


Well I had to solder some RCA connector to it which is a pain.

-It solves the problem but there is a catch. Even with the gain set at maximum on the SNI-35, now the audio is not loud enough.
I tried to go to the factory menu with "126" code and set audio outputs all to max, and set amplifier to 0db max also.
It is okay when cruising on motorway, but not loud enough with windows open etc.

The SNI-35 has a audio transformer. It is said to break the ground loop problem. It has also a gain amplifier that in our case reduces too much the volume. It's purpose it to pick the audio signal when connecting a Subwoofer or amplifier.

If you really try you can still here the problem with the engine stopped but it's very very faint. This tells me that the ground loop isolator doesn't fix the problem. It is only because the gain has been lowered, so are the signal parasites.

To me the big problem resides in the amplifier power circuit on these cheap Android HU. The power circuit is not well build nor isolated.

I have a question for you :

- Do the output volume change when your engine is on load ?

To be more precise, when there is load on the alternator. When going uphill for example the volume raises about 25% then drops if I take my foot of the pedal. It has no relation with reving the engine strangely, it seems that when the alternator gives 14V the audio volume raises. This seems to show up that the Android HU is not well built.

This takes too much time. I will try to put a ground loop isolator filter on the power input of the HU as last resort !
 

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jason hui

Registered User
I had been racking my brain on this problem on my 2012 A3 with BOSE. the static, humm, and engine whine was frustrating. I finally scoured through many forums and found my solution in a wiring diagram. I'm sharing this so that someone will be able to search and benefit from my time labored work.

for your information regarding the wiring of this stereo into an A3 with Bose and Non Bose.

non Bose stereo - amplifier run the rear speakers. the Head Unit has amp that operate the front speakers. the wiring plug on this stereo has direct wires to front speakers, a high level output. the rear speakers go to the amplifier, the the head unit has a low level output for the rear speakers.

The Bose Stereo, like the one I have, have a amp to all the speakers. so the original head unit has low level output to the amplifier.

the reason for the static, humm, and engine whining, is because the way Xtron wired the stereo to output to all the speakers from the internal amplifer, thus it is a high level output. a high level output will cause issues when going to an external amplifier set up for low level input. basically, you can connect amplifiers in series.

I took the speaker wires from the back of the stereo socket and connected it to the RCA output from the stereo. Thus creating a low level output connection to an external amplifier that only accepts low level input. no more static, humm, or engine whine.

i recommend that you create the proper connections for future stereos to match the type of stereo that they have from the factory. its obvious this stereo is wired to connect directly to the speakers and not to an amplifier

no need for inline power filter, no need for ground loop isolators. just needed to know that there is an amplifier living in the car and to wire appropriately.
 

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Sonnyxxx

Registered User
I had been racking my brain on this problem on my 2012 A3 with BOSE. the static, humm, and engine whine was frustrating. I finally scoured through many forums and found my solution in a wiring diagram. I'm sharing this so that someone will be able to search and benefit from my time labored work.

for your information regarding the wiring of this stereo into an A3 with Bose and Non Bose.

non Bose stereo - amplifier run the rear speakers. the Head Unit has amp that operate the front speakers. the wiring plug on this stereo has direct wires to front speakers, a high level output. the rear speakers go to the amplifier, the the head unit has a low level output for the rear speakers.

The Bose Stereo, like the one I have, have a amp to all the speakers. so the original head unit has low level output to the amplifier.

the reason for the static, humm, and engine whining, is because the way Xtron wired the stereo to output to all the speakers from the internal amplifer, thus it is a high level output. a high level output will cause issues when going to an external amplifier set up for low level input. basically, you can connect amplifiers in series.

I took the speaker wires from the back of the stereo socket and connected it to the RCA output from the stereo. Thus creating a low level output connection to an external amplifier that only accepts low level input. no more static, humm, or engine whine.

i recommend that you create the proper connections for future stereos to match the type of stereo that they have from the factory. its obvious this stereo is wired to connect directly to the speakers and not to an amplifier

no need for inline power filter, no need for ground loop isolators. just needed to know that there is an amplifier living in the car and to wire appropriately.


Hi Jason,


Thanks for taking the time to try and help others. I'm in a similar situation. Full BOSE setup, horrible alternator whine and static. I've tried ground loop isolators, power noise filters and ferrite cores.

I'm struggling to fully understand what you mean by "I took the speaker wires from the back of the stereo socket and connected it to the RCA output from the stereo."

Could you clarify please?

On my headunit, it fits directly onto the factory quadlock. But I may have to use the alternative means of connecting it via the provided RCA cables and other connections that plug into the back of the stereo. In an attempt not to have to do that, I've purchased this: https://audiotechdirect.com/direct-fit-audi-bose-rca-adaptor-for-audi-es-dj-series-units/

In combination of plugging the quadlock directly into the back of the head unit, and connecting any wires that were missed to the alternative means of connection I'm hoping this will fix my whine but you seem to have a better idea of what the problem is exactly.

This is the back of my headunit and the cables it comes with:

ES5147A-E19-Wiring-Diagram.jpg


Thank you,

Sonny
 
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jason hui

Registered User
From the wire diagram I posted. Find cluster c from OEM connector coming from the car. Take cluster c plug out, it just unclip from the main cluster.

Use the wire diagram to determine the wires for the different speakers.

Take a short RCA wire with left and right channels and cut in half. Use the halves to tap into the wires for the different speakers. Note: I did not cut the c plug off, I tapped into the wire only because I never liked cutting OEM connectors.

The bare wire inside the RCA wire is the ground. Connect all of them together to form one wire and tap into the ground wire as indicated in c.

The RCA wires plug into the preamp output from new stereo.


From your picture. It looks like your stereo is the same as mine. So here is another tip that the company didn't tell me from the beginning. Since you don't need that other cluster of wires because our Bose stereo connector matches the new stereo. Don't throw that aside. There is a small cluster of wires, f, that a red wire is the only wire connecting them together. Cut that red wire and use the small ,f, connector. It is your reverse camera input.

e19e3c5f63216929c64152399967787c.jpg


Sent from my ONEPLUS A6013 using Tapatalk
 

Sonnyxxx

Registered User
From the wire diagram I posted. Find cluster c from OEM connector coming from the car. Take cluster c plug out, it just unclip from the main cluster.

Use the wire diagram to determine the wires for the different speakers.

Take a short RCA wire with left and right channels and cut in half. Use the halves to tap into the wires for the different speakers. Note: I did not cut the c plug off, I tapped into the wire only because I never liked cutting OEM connectors.

The bare wire inside the RCA wire is the ground. Connect all of them together to form one wire and tap into the ground wire as indicated in c.

The RCA wires plug into the preamp output from new stereo.


From your picture. It looks like your stereo is the same as mine. So here is another tip that the company didn't tell me from the beginning. Since you don't need that other cluster of wires because our Bose stereo connector matches the new stereo. Don't throw that aside. There is a small cluster of wires, f, that a red wire is the only wire connecting them together. Cut that red wire and use the small ,f, connector. It is your reverse camera input.

e19e3c5f63216929c64152399967787c.jpg


Sent from my ONEPLUS A6013 using Tapatalk



Thanks for the help Justin. It is really appreciated.

So from your diagram, we both have a cluster of wires marked as 'C'. You found the equivalent of the C cluster in the OEM Quadlock connector. We will call this "OEM C". You unplugged this section of the quad lock connector. The rest of the quad-lock, (the square black plastic with lever clip) goes into the back of the unit.

Now, you do plug the C cluster provided with the head unit kit into the back of the head unit. You then connect this C cluster with the OEM C cluster?

You mention getting a short RCA cable, is this a separate RCA cable I should go and buy, or are you referring to the RCA cables in the C cluster? I am also not sure what you mean by tap into ground wire as indicated in C.

Are you saying to take the OEM speaker wires coming from the car, convert them into RCA cables, then plug those into the C connector that is plugged into the head unit?

Sorry if I'm not understanding well. I am a little confused. You will have to explain it in more detail for me to understand, I am sorry.

Any pictures would be greatly appreciated, but I know this may be a lot of hassle to take the head unit out of the dashboard so do not worry about this if it is. Thank you for the tip about cutting the red wire.

Thanks for the help so far!
 

jason hui

Registered User
No worries.
It
Buy RCA wire and cut in half

Strip the cut ends and expose the wires

The bare wire is neg and the inner wires are positive.
Look for the large square connector from the car.

Disconnect c from the larger connector.

Identify the speaker wires in c

Connect the exposed end of the RCA wires to c. It's up to you to cut the connector of or just tap into the wires.

Make sure the connection is tight and tape it to shield from surrounding emf.

Now the speaker wires have RCA connections.

From your new stereo, your cluster A has RCA output. Connect those to your new RCA connectors.

The purpose is that you r trying not to use your new head unit amplifier. Because u should never connect two amp in series.


Sent from my ONEPLUS A6013 using Tapatalk
 

jason hui

Registered User
To anyone else reading this, the Bose system speakers are run by an external amp. That's for front and rear.

The non Bose in later years, the front speakers r powered by head unit and the rear speakers are powers by external amp. So if ur having issues with the rear volume not matching the front and/or feedback in the rear, refer to what I did to use the preamp outputs only for the rear.

The earlier models had head units that powered all speakers, do not have external amp. So those r just plug and play, no issues.

So keep that in mind when wiring.

Sent from my ONEPLUS A6013 using Tapatalk
 

COASTER19

New Member
This is true, but it's a little more complicated than that. Or at least it is on my A3 8P 2011 Bose with PX6 radio. I've been working on tracking down the source of this noise for a month now and think I finally have it figured out.

The buzz and hiss people often talk about with this model are often a combination of 2 separate sources:
1. Poor quality of the line level outputs on these, this is why you can hear it when the GPU or touchscreen is in use on some android radios. The same does NOT apply to the speaker level outputs as the circuitry generating the sound is physically closer to the amplifier than the line level output.
2. Induced noise on the line to the external Bose amplifier. This is where the alternator whine and buzzing when braking/signaling comes from.

Of these, the second is by far the bigger problem, but also the harder to solve. Both of the radios I have ordered arrived with the correct harness for using the line level output. This doesn't produce the best (or even acceptable) sound quality in my opinion.

The reason this is a problem is that the external amplifier expects a signal with low output resistance, and most radios cannot provide that (or at least the two I have, one 8227L and one PX6). If you wire the line level outputs directly to the Bose amplifier input you will get sound, but it isn't powerful enough to prevent the induced alternator whine and buzzing when you press the brake pedal or use the right turn signal. The external amplifier inputs actually consume current, far more than your typical headphones. When they aren't driven with a low enough source resistance, they are susceptible to noise and sound quality suffers. You can verify this for yourself easily by unplugging the RCA inputs to the external amplifier - the buzz will be worse than ever, and will be attenuated to different degrees by bridging a resistor across the input. For it to all go away, the resistor needs to be less than 10 ohms. This is crazy low, as even 100kohm will make a regular amplifier input be quiet. This means there must also be very poor shielding between the amp and the input and I'm surprised this appears to be the case given that they put the Bose name on it.

(too long a post, splitting up to be able to submit)
 

COASTER19

New Member
This leaves 2 options to fix it:
1. Take the line level outputs and buffer them with opamps or some other high quality linear regulator. Theoretically this will produce the cleanest sound, as it is only amplified once, in the external amp. Unfortunately the sound quality from them isn't great, so the benefits of being line level the whole time are wasted.
2. Use a speaker level to line level transformer, as this provides the current driving capability. Resistor dividers WILL NOT WORK, as they increase the impedance of the line to the external amplifier and actually make the alternator whine worse.

Considering the relatively poor quality of the line level output from these, I would recommend going with the second option. The speaker output is far cleaner looking on the oscilloscope than the line level output, and converting it to line level doesn't impact the waveform until you get below 20Hz.

I used an AP3044 but an SNI-35 or similar should work just as well, just make sure to wire it to the speaker level outputs, not the line level outputs.

The final thing to do if you have Bose is to enable the external amplifier's EQ, which can be done by adding a header on the quadlock for connector B, pin 7, and tying it to ground (you can find the wiring diagram on top of any RNS-E). I highly recommend checking that this is indeed an input with a multimeter set to current mode, as apparently some older A3s have this pin as a clock, and you never want to connect a driven pin to ground. In my case the pin showed no clock signal on the oscilloscope, and passed 2mA when shorted to ground. The sound profile changed for the better too, I'm surprised they didn't have the pin installed by default.

I'm disappointed there is not a better solution, but for as long as these radios continue to have poor line level output quality I believe this is the best that can be done. The result is great to my ear once I tune my DSP levels appropriately, so I would consider this a true solution despite it being poor practice to amplify, reduce, and re-amplify a signal.
 

Shammy786X

New Member
I had been racking my brain on this problem on my 2012 A3 with BOSE. the static, humm, and engine whine was frustrating. I finally scoured through many forums and found my solution in a wiring diagram. I'm sharing this so that someone will be able to search and benefit from my time labored work.

for your information regarding the wiring of this stereo into an A3 with Bose and Non Bose.

non Bose stereo - amplifier run the rear speakers. the Head Unit has amp that operate the front speakers. the wiring plug on this stereo has direct wires to front speakers, a high level output. the rear speakers go to the amplifier, the the head unit has a low level output for the rear speakers.

The Bose Stereo, like the one I have, have a amp to all the speakers. so the original head unit has low level output to the amplifier.

the reason for the static, humm, and engine whining, is because the way Xtron wired the stereo to output to all the speakers from the internal amplifer, thus it is a high level output. a high level output will cause issues when going to an external amplifier set up for low level input. basically, you can connect amplifiers in series.

I took the speaker wires from the back of the stereo socket and connected it to the RCA output from the stereo. Thus creating a low level output connection to an external amplifier that only accepts low level input. no more static, humm, or engine whine.

i recommend that you create the proper connections for future stereos to match the type of stereo that they have from the factory. its obvious this stereo is wired to connect directly to the speakers and not to an amplifier

no need for inline power filter, no need for ground loop isolators. just needed to know that there is an amplifier living in the car and to wire appropriately.

Hi Jason, i ordered an extension quadlock cable and it came today. didn't want to rip apart the factory harness so this was a viable option and cheap too. So i cut the wires, attached all the grounds of the Rca's to pin 8 (Bose signal earth), each postive pin of the RCA to the each remaining bose amp cable. so i plugged it in, no weird whining, interference but when I play music it's a lot quieter compared to the normal output. not only that but only the rear left side would play most of the sound whilst there was a very little amount of sound from the others. i have a feeling it's the way Xtrons have set the outputs to the RL,RR,FR,FL RCA outputs but it doesn't make any sense as to why they would label the cables correctly but not function correctly. did you come across an issue like this at all?
 
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