XTRONS MTCD - Weak Bass - HW Audio MOD

[haakjoringskod]

PA79ATTIP

Hi everyone, did anyone else try this mod and can share his/her experience?
I have exactly the same issue with my Xtrons PA79ATTIP Android 9.0 which I put into my Audi TT MK2.
Anyone here who could assist me with some detailed explanations. To be honest, I am absolutely new to this.
However, I would be happy to get back a decent level of audio quality.

Btw. is there anyone else having issues with noise coming from the speakers when you turn on the light and/or driving faster?
I was reading this can be handled with noise filter adapters (maxxcount NF-Entstörfilter)?

 

[skezza]

In my Audi, the bass did feel disappointingly weak, until I activated Loudness. Wow. The sound quality difference is insane. It's gone from being a weak little radio to being a beast. Very surprised. It might be worth a try.

 

[haakjoringskod]

Thank you!
I already tried it out, but it just helped a little bit. I am still suffering loss of performance compared to the original Audi radio.
Tawin01 said even the Viper4Android wasn't making any improvement. Does anyone else have experienced here equal results?

 

[typos1]

Thank you!
I already tried it out, but it just helped a little bit. I am still suffering loss of performance compared to the original Audi radio.
Tawin01 said even the Viper4Android wasn't making any improvement. Does anyone else have experienced here equal results?
Also I read about a sound mod to modify the MCU. But this seems to be just for PX3/PX5 radios. I don't know if this also works for my PA79ATTIP?

What do you mean by "weak performance" ?

Do you have the standard set up, the amplified rear or the Bose setup ?

 

[haakjoringskod]

Amplified rear setup

What do you mean by "weak performance" ?

Do you have the standard set up, the amplified rear or the Bose setup ?

It is hard to explain, but it sounds very thin and sharp compared to my previous setup.
I do have the amplified rear setup. I also get sound from behind, but as I have described above it does not provide a fully smooth output as before. The subwoofer quality is missing some detail.

 

[typos1]

It is hard to explain, but it sounds very thin and sharp compared to my previous setup.
I do have the amplified rear setup. I also get sound from behind, but as I have described above it does not provide a fully smooth output as before. The subwoofer quality is missing some detail.

Are you sure the amp for the rear speakers is turning on ? Sounds like it isnt.

 

[haakjoringskod]

Are you sure the amp for the rear speakers is turning on ? Sounds like it isnt.

Well when I set the EQ Fader all to the back, all of the rear speakers were having sound. So I guessed everything was working. Otherwise I wouldn't have any sound at all, wouldn't I?

However, I noticed that Xtrons says that it was necessary to make some modification to the wiring, in case it wasn't a Bose setup. Since I got sound from the rear speakers I assumed it worked without any wire modifications.

 

[typos1]

Well when I set the EQ Fader all to the back, all of the rear speakers were having sound. So I guessed everything was working. Otherwise I wouldn't have any sound at all, wouldn't I?

However, I noticed that Xtrons says that it was necessary to make some modification to the wiring, in case it wasn't a Bose setup. Since I got sound from the rear speakers I assumed it worked without any wire modifications.

The rear speakers will work if theyre connected to speaker wires, but if the amp isnt turned on they wont be amplified, you need to find out what wire on the car triggers the rear amp, Google it I m sure theyll be loads of info, its a common set up with VW/Audis, then you can verify if the amp is coming on or not.

 

[haakjoringskod]

The rear speakers will work if theyre connected to speaker wires, but if the amp isnt turned on they wont be amplified, you need to find out what wire on the car triggers the rear amp, Google it I m sure theyll be loads of info, its a common set up with VW/Audis, then you can verify if the amp is coming on or not.

Unfortunately I cannot share any links here, but I was following the Xtrons instructions called "Enable Sound Out of Audi Rear Speakers".
When it comes to the step "If your vehicle does not have the BOSE system, but has the audio port as the below picture shows, you will still be required to make some modifications to the wire connections. If you do not, your rear speakers will NOT have sound." I am completely sure this does not apply to me. I mean I have neither a Bose setup, nor do I have "the audio port as the below picture shows". I simply connected all the ISO cables and RCA cables as described by Xtrons. And there were no cables from my car left after I have connected everything together.

All in all this leaves me with these two issues:

1) Humming / whining noise when turning on the lights / starting the car
2) Lack of audio quality

I will try to use a filter for the first issue. Regarding the sound quality I will give the sound mod a try. However, I also read about a PAC SNI-35 Line-Out Converter. But I do not know how to connect these to my Xtrons headhunt…

 

[typos1]

Unfortunately I cannot share any links here, but I was following the Xtrons instructions called "Enable Sound Out of Audi Rear Speakers".
When it comes to the step "If your vehicle does not have the BOSE system, but has the audio port as the below picture shows, you will still be required to make some modifications to the wire connections. If you do not, your rear speakers will NOT have sound." I am completely sure this does not apply to me. I mean I have neither a Bose setup, nor do I have "the audio port as the below picture shows". I simply connected all the ISO cables and RCA cables as described by Xtrons. And there were no cables from my car left after I have connected everything together.

All in all this leaves me with these two issues:

1) Humming / whining noise when turning on the lights / starting the car
2) Lack of audio quality

I will try to use a filter for the first issue. Regarding the sound quality I will give the sound mod a try. However, I also read about a PAC SNI-35 Line-Out Converter. But I do not know how to connect these to my Xtrons headhunt…

I wouldnt take too much notice of Xtrons.

The humming is a ground loop issue, you ll need a ground loop isolator, they are threads in this and the related MTCB units forum, also on google, its a common Audi issue.

For the sound issue you need to establish that you deffo have amplified rear speakers and that if so that the amp is deffo coming on, if you have one and it isnt coming on it should solve your issue.

 

[haakjoringskod]

I wouldnt take too much notice of Xtrons.

The humming is a ground loop issue, you ll need a ground loop isolator, they are threads in this and the related MTCB units forum, also on google, its a common Audi issue.

For the sound issue you need to establish that you deffo have amplified rear speakers and that if so that the amp is deffo coming on, if you have one and it isnt coming on it should solve your issue.

I have solved the humming and whining noise issue with two filters purchased from maxxcount. Probably others would have done the same job. But those worked for me!

Also I have installed the patched sound mod. It got a little bit better, but I am still not perfectly satisfied. Do you think an additional plug and play DSP Amp (cf. androidautoshop) would do a good job here?

 

[typos1]

I have solved the humming and whining noise issue with two filters purchased from maxxcount. Probably others would have done the same job. But those worked for me!

Also I have installed the patched sound mod. It got a little bit better, but I am still not perfectly satisfied. Do you think an additional plug and play DSP Amp (cf. androidautoshop) would do a good job here?

I think you should check that your amp is actually working, as I said before.

 

[pedracca]

I wouldnt take too much notice of Xtrons.

The humming is a ground loop issue, you ll need a ground loop isolator, they are threads in this and the related MTCB units forum, also on google, its a common Audi issue.

For the sound issue you need to establish that you deffo have amplified rear speakers and that if so that the amp is deffo coming on, if you have one and it isnt coming on it should solve your issue.

Sorry for the thread resurrection. I have an Xtrons (GS) and an Audi, and the whine noise is driving me crazy. I've relocated fifty times the small RCA board and made a case for it, and despite having got rid from the whine noise with stopped engine, it is always there again as soon as I turn on the engine.

I've been searching on the forum and I'm trying the ground loop isolator solution but I am not sure which type should I buy. Are you speaking of an RCA ground loop isolator or one for the battery feed to the HU? Could you recommend an specific model so I don't mess up?

If it is a RCA type that is needed, do they harm sound quality?
If it is for the battery current, where is it connected? After the quadlock? Only on battery + or ACC too?

Thank you!

 

[typos1]

I m sorry I not certain what type of ground loop isolator you need because I ve never needed to use one, I would guess a battery one but I m not certain, google it too, I think its a common problem.

 

[pir8man]

Sorry for the thread resurrection. I have an Xtrons (GS) and an Audi, and the whine noise is driving me crazy. I've relocated fifty times the small RCA board and made a case for it, and despite having got rid from the whine noise with stopped engine, it is always there again as soon as I turn on the engine.

I've been searching on the forum and I'm trying the ground loop isolator solution but I am not sure which type should I buy. Are you speaking of an RCA ground loop isolator or one for the battery feed to the HU? Could you recommend an specific model so I don't mess up?

If it is a RCA type that is needed, do they harm sound quality?
If it is for the battery current, where is it connected? After the quadlock? Only on battery + or ACC too?

Thank you!

An RCA type ground loop isolator will definitely loose sound quality. They are a band-aid to hide the problem, not a fix. It is strongly recommended to find and solve your ground loop issue instead.
Power based loop isolator should be connected to either or both your 12v power sources (batt/acc). If only one is causing the ground loop, you only need to do that one.
In the process of testing, with a multimeter, for where you might want a power isolator, you will have all the information to actually solve your ground loop and can solve it without adding a power filter.

I threw power isolators on both of my input voltages and they did not solve a thing for me. I also ruled out my RCA cables being the cause of my ground loop, so the ground wire around the RCAs hack would not work for me either. Tomorrow I am pulling my multimeter out of storage to do some proper ground loop diagnosis.

 

[pedracca]

An RCA type ground loop isolator will definitely loose sound quality. They are a band-aid to hide the problem, not a fix. It is strongly recommended to find and solve your ground loop issue instead.
Power based loop isolator should be connected to either or both your 12v power sources (batt/acc). If only one is causing the ground loop, you only need to do that one.
In the process of testing, with a multimeter, for where you might want a power isolator, you will have all the information to actually solve your ground loop and can solve it without adding a power filter.

I threw power isolators on both of my input voltages and they did not solve a thing for me. I also ruled out my RCA cables being the cause of my ground loop, so the ground wire around the RCAs hack would not work for me either. Tomorrow I am pulling my multimeter out of storage to do some proper ground loop diagnosis.

Thank you! That's what I suspected with RCA filters after googling it. I've spent a considerable amount of money and time upgrading the equipment recently (the only thing left untouched are rear speakers and HU) so I'd like to avoid them.

Problem got really worse after upgrading, I had whines before with factory setup, but they were solved relocating the RCA board the op is referring to. Not anymore, whatever I do with the board, once the engine is on the whine kicks in (it is quiet with engine off). Although all the googling I made points out an installation problem with amp ground and/or cable routing, it is worth noting that I installed a kit sold by Audi (manufactured by Alpine) that uses all the factory cabling, only the components themselves where changed, so I am assuming it is not an amp ground or cabling problem.

I only know the basics using a multimeter, so I'll try to isolate the problem connecting and disconnecting the different elements that are connected to the HU (front and rear cam, usb wifi module, etc.). I'll connect the factory HU too to test if it is 100% HU related or not.

Also, bought a power filter made by Sinuslive brand, don't know if it will be any good yet. I only have one so I'll connect both the HU battery and acc to the filter and see how it goes.

If I find out anything interesting I'll report back.

Please, keep us posted. Thank you again.

 

[pedracca]

I've been trying to find a solution this weekend.

- First I went one by one disconnecting all the extra devices (front and rear cam, antenna, usb, etc.). I only left the minimum cabling to get sound. This didn't solve it. If I unplugged the RCA's, sound and hiss went away, so it seemed like the HU itself was guilty.
- I then tried the factory HU = Absolutely no hiss, perfect sound. That made it clear the android HU is guilty.
- Finally tried the filter, and that did the trick ...almost.

The hiss is indeed reduced, but it is still there. I'd say it's been cut by two thirds. It has gone from completely unbearable to bearable, but it is still noticeable and while this will be a short term solution, I suppose I'll end up buying a head unit from any reputable brand, as this looks like the only way to get rid of the hiss.

Good luck with yours.

 

[typos1]

Its deffo something on the car that cause it cos its only Audis that have this problem, other cars dont. It would be good to try and find out what is different about Audis that CAN cause this (it doesnt always happen to every Audi).

Those "reputable" brands you talk of, they have mostly the same components inside, the amp chips for instance.

 

[pir8man]

Thank you! That's what I suspected with RCA filters after googling it. I've spent a considerable amount of money and time upgrading the equipment recently (the only thing left untouched are rear speakers and HU) so I'd like to avoid them.

Problem got really worse after upgrading, I had whines before with factory setup, but they were solved relocating the RCA board the op is referring to. Not anymore, whatever I do with the board, once the engine is on the whine kicks in (it is quiet with engine off). Although all the googling I made points out an installation problem with amp ground and/or cable routing, it is worth noting that I installed a kit sold by Audi (manufactured by Alpine) that uses all the factory cabling, only the components themselves where changed, so I am assuming it is not an amp ground or cabling problem.

I only know the basics using a multimeter, so I'll try to isolate the problem connecting and disconnecting the different elements that are connected to the HU (front and rear cam, usb wifi module, etc.). I'll connect the factory HU too to test if it is 100% HU related or not.

Also, bought a power filter made by Sinuslive brand, don't know if it will be any good yet. I only have one so I'll connect both the HU battery and acc to the filter and see how it goes.

If I find out anything interesting I'll report back.

Please, keep us posted. Thank you again.

I ran through some ground tests Found that my Amplifier ground point has 0.1 Ohm resistance. Well within the 0.5 Ohm suggested limit for a ground point.
Then I moved to testing the head-unit, where the OEM harness ground was 1.1 Ohm. Way too high. I found a nice grounded bolt behind the unit with a 0.1 Ohm resistance (Equal to the amplifier, so no ground-loop). Temporarily connected the stereo ground to this and found it cut about half of my engine noise! I cut the OEM ground wire and ran it to the better ground location.
Next thing to test for was a dirty(noisy) positive wires. Sure enough, I ran a fused wire directly to the battery and temporarily connected the yellow and red positive wires from my radio from the new battery lead. This resolved all my extra noises. I finally have clean sound coming from my speakers!!

Based on the research I did before heading out to test my car, I found that it is not uncommon at all to find that the OEM ground is insufficient for a higher-powered aftermarket stereos. Manufacturers only put in a 'just good enough' ground wire/ground point for the low-power OEM unit.
The same is true with power leads. The OEM unit can use dirty power leads and never pass the noise to your speakers. Where an aftermarket unit will amplify this extra noise and pass it on to your speakers/amplifier.