[carlr]

For those who have located the H/K amp in the back - do you know if it is being fed via MOST or other signal?

[ramparts]

Originally Posted by carlr

For those who have located the H/K amp in the back - do you know if it is being fed via MOST or other signal?

For Idrive 7, there's an Ethernet connection between the head unit and the RAM module in the trunk. The RAM has analog outs for most of the channels, but also a connection to the "booster" ( the dodgy part ). That feeds the bass speakers

[srbs73]

I took my March 2020 build G21 in this week and all they've done is upgraded the iDrive to 03/2021.50. I assume this will make no difference but will have to wait for the issue to reoccur and send it back in.

[ramparts]

Originally Posted by srbs73

I took my March 2020 build G21 in this week and all they've done is upgraded the iDrive to 03/2021.50. I assume this will make no difference but will have to wait for the issue to reoccur and send it back in.

The EQ definitely sounds diffferent post 03/21.
I'd had my amp replaced a month before that "fixed" the issue, but then the istep improved the sound stage

[zordon]

I had this issue as well. Last month, I researched and ran into this forum: https://g20.bimmerpost.com/forums/sh....php?t=1781851

At first I referenced the service bulletin, but SA said it didn't pertain to my car VIN. And since they couldn't reproduce the sounds, they said to take notes, record it and then bring it back in. I was able to record the bass going completely out and text the SA the video. He told me to bring it and it was replaced within a day.

[srbs73]

Originally Posted by zordon

I had this issue as well. Last month, I researched and ran into this forum: https://g20.bimmerpost.com/forums/sh....php?t=1781851

At first I referenced the service bulletin, but SA said it didn't pertain to my car VIN. And since they couldn't reproduce the sounds, they said to take notes, record it and then bring it back in. I was able to record the bass going completely out and text the SA the video. He told me to bring it and it was replaced within a day.

I will do that next time

[MadMaxy]

My F44 lost the bass. One time it was working, one time it was not... went to dealer - next day - "Amplifier replacement"... Car had 8000km (like 5000-6000miles) and it was 1Y old.

Of course when I went to a service - bass was working fine, so have no idea how they managed to check that and confirmed it's amplifier failure.

[Lonmon]

I have this issue with popping noises (I think more often when cold) and only on a couple of occasions the bass disappear. Since my car is tuned I have hesitated to take it in to BMW since it is so rare that it impedes me enjoying the car ever day.

I have however developed another issue that I'm wondering if anyone else has experienced. Every couple times I drive the car, between 20-40 mins into a drive the idrive system reboots itself. It works fine after it reboots but it is annoying in the middle of navigation, or music it randomly reboots itself.

It all started about 8mths into ownership when the bass cut out on me and I tried to reboot it while driving by holding the volume knob down for like a min. Since then I have tried holding the volume button to hard reset a couple times, recoding the radio ecu with Bimmercode, and reflashed the dme. Only thing I haven't tried is disconnecting both batteries yet.

[srbs73]

Originally Posted by zordon

I had this issue as well. Last month, I researched and ran into this forum: https://g20.bimmerpost.com/forums/sh....php?t=1781851

At first I referenced the service bulletin, but SA said it didn't pertain to my car VIN. And since they couldn't reproduce the sounds, they said to take notes, record it and then bring it back in. I was able to record the bass going completely out and text the SA the video. He told me to bring it and it was replaced within a day.

Managed to record this after a number of months and finally got the amp replaced last week

[pedro_no1]

very strange thing with the cars that are recalled in service for this problem because I have the same problem (lowering the bass but only when I listen to Radio) and it is random and quite rare, in 5 months since I have the car I could only notice this twice ... the car in question G20 330d M Sport 07/2019 with (S6U3) BMW Live operating area Professional and (S688) Harman / Kardon surround sound system.

Anyway, I will pay a visit to the BMW dealership very soon (I still have a car warranty) because I have other problems (aka known issues) such as the noise from the sunroof and the rear-view mirrors do not fold after washing the car. .. I don't know if the paint that jumps off the hood from all kinds of small stones also comes under warranty!

[Fiskk]

So this issue is SUPER annoying! I run a 330e g21 that had this issue from start. First time i had BMW look at it they did a code upgrade on iDrive. Didnt solve the issue.

Next time a couple of months later they accually replaced the "boooster"(or what they called it, the AMP..).

It took only a couple of weeks and the issue is present again. bass drops, clicks and popping in speakers..

I hate it so much since playing music when driving is key. I need it to feel good. I love driving but this shit is getting to me badly.

I will now once more book a time for fix at BMW dealer. My guess is that they will replace it with the same type of part and issue will come back again in some weeks..


EDIT:
please note that it was about 6 months ago i had amp replace. not sure if i got a diffrent model than original or a newer better one? where is it located?


/M

[srbs73]

On my warranty invoice, the code is the same as this one:

https://static.nhtsa.gov/odi/tsbs/20...88953-9999.pdf

[Squintstream]

I seemed to have the same issue… a sporadic drop in bass, where the under-seat subs and bass drivers were not providing anything and only the tweeters and mids were providing sound, but others time (getting in the car), everything seemed to be fine!

Here’s my experience in the UK with this fault.

- Took the car into my dealer along with a printout of the original BMW DE email.
- They had the car for a day and did various tests and system updates. However, to my knowledge no new parts were installed.
- Picked up the car the following day and everything seems to be working fine, although I’m a little disappointed that a new booster wasn’t fitted as a matter of course.

I’ll closely monitor this moving forward and if I notice the same again, at least I’m on the system having raised this fault.

[Fiskk]

Originally Posted by Fiskk

So this issue is SUPER annoying! I run a 330e g21 that had this issue from start. First time i had BMW look at it they did a code upgrade on iDrive. Didnt solve the issue.

Next time a couple of months later they accually replaced the "boooster"(or what they called it, the AMP..).

It took only a couple of weeks and the issue is present again. bass drops, clicks and popping in speakers..

I hate it so much since playing music when driving is key. I need it to feel good. I love driving but this shit is getting to me badly.

I will now once more book a time for fix at BMW dealer. My guess is that they will replace it with the same type of part and issue will come back again in some weeks..


EDIT:
please note that it was about 6 months ago i had amp replace. not sure if i got a diffrent model than original or a newer better one? where is it located?


/M

Ok so I just got my car picked up the third time for this issue.

1st time software upgrade.
2nd time, replace booster
3rd time software upgrade......

Where exactly is the booster located? I want to see which model i have installed, since its been at least 6 months since they replaced it.

its been working for 24 hours now without pops or bass drops etc, but im not fully convinced yet that the issue is solved.
will report back if any changes.

[DeathBlade]

Hopefully I can provide insight here as I don’t think this has been posted yet to this capacity. So I had the same issue going on with my 20 g20 and had it at the dealer 3 times for the issue but they said nothing was ever found wrong and blamed it on CarPlay. So I decided to take the issue on myself and gather as much proof as I could. I setup a GoPro in my car and every time it popped and had a bass cut I stopped the clip. And restarted the camera. After about a week of doing this, on my way home I had a complete cut and it did not recover. Had this happened many times and I know just letting the car sit for 30 minutes will “fix” it unless you are impatient and on a road trip and disconnect the batteries because you don’t want to wait. Anyway when I got home I did not shut the car off and went inside grabbed my Carly adapter and my laptop and enet cable and screen recited reading the codes from both. I had two codes in the AMP “031D15” and “031D19”. Oddly enough these codes clear on their own which makes sense why the dealer never saw anything. I made another appointment took everything in and the senior tech that took over my car since this was the third time I had it in for this talked to me and said this is strange. The SIB did not apply because the codes are different however the codes had a different test plan in ista which takes a full day as it involves taking seats out and checking wiring front to back for damage that may have occurred during assembly. Anyway after they confirmed that wiring was not an issue he actually managed to hear it pop once and was able to see the codes I had as well. In the end they did replace the booster same as if the SIB did apply but it just took a lot of extra steps.

Hope this long explanation can help someone as I know I was very upset that my brand new custom ordered car was doing since first week of ownership back in 2020.

[b46driver]

I know the PUMA is for 20/21, but I have a '19 G20 that needs the amp replaced.

Sound goes out on my front left tweeter and sometimes it will just crackle and make popping sounds. Doesn't happen until I've driven the car for some time and it's gotten warmed up, but definitely a recurring thing.

Part, of course, is on backorder, and they're saying September for delivery...

[ramparts]

Originally Posted by b46driver

I know the PUMA is for 20/21, but I have a '19 G20 that needs the amp replaced.

Sound goes out on my front left tweeter and sometimes it will just crackle and make popping sounds. Doesn't happen until I've driven the car for some time and it's gotten warmed up, but definitely a recurring thing.

Part, of course, is on backorder, and they're saying September for delivery...

That doesn't sound like the booster is an issue here, as the tweeters don't run off it. Also, your mid would fail at the same time due to how they are wired.

Sounds more like bad wiring from the tweeter to the mid range speaker that, as it runs up the door trim into a pinch point

[b46driver]

Originally Posted by ramparts

That doesn't sound like the booster is an issue here, as the tweeters don't run off it. Also, your mid would fail at the same time due to how they are wired.

Sounds more like bad wiring from the tweeter to the mid range speaker that, as it runs up the door trim into a pinch point

Sure, except they kept it an extra day or so to call up HQ in Germany. They wanted to make sure that it wasn't the wiring which is cheaper to fix before they decided to send out a much more expensive and backordered part. They're sending the part, so it doesn't seem like it's a wiring issue. They're sending amp, not booster.

[Technic]

Originally Posted by b46driver

Sure, except they kept it an extra day or so to call up HQ in Germany. They wanted to make sure that it wasn't the wiring which is cheaper to fix before they decided to send out a much more expensive and backordered part. They're sending the part, so it doesn't seem like it's a wiring issue. They're sending amp, not booster.

For clarity, BMWAG is replacing your RAM, not the Booster.

[BMW5and7]

Any definitive solution to this issue so far? Just had this happened to my X7. No Bass…. Turned off the car for 1-2 hours, back to it, and sound is fine…

[Steadyhand]

This is happening in my X3M (F97/G01) that has the HK sound (688) with RAM module/booster. My X3M borne date is 2/14/2021 and the RAM module date is 4/2021 (suppose the 4th week of 2021). The model number on my RAM module is 'supposed' to be the correct, improved, working RAM module, yet I have near zero bass from under the seats.

[tester2011]

Can someone point me to where the amp is actually located?

Thank you