Stereo Woes

[Mayan-Viking]

Some time ago I upgraded to an Avin head unit and BAVSound speakers at the same time. Since then I have been getting lower frequency distortion in the right door panel driver. I'm pretty sure this distortion was not happening before swapping everything out.

I got in touch with BAVSound and was able to get new speakers shipped to me. I replaced the speaker and I am still getting the same distortion.

I then replaced the OEM HK amp with a replacement amp from eBay and again I am getting the same distortion.

At this point I am thinking it HAS to be the head unit that is faulty and causing the distortion (which sucks because I'm not looking forward to dealing with Avin's customer support in this matter). Is there anything else I am missing in this analysis of where the fault could lie?

[maw1124]

No, unfortunately.

The last test you can run easily is your stock head unit with the BavSound speakers and HK amp, which will likely answer your question for good AND sound better than the Avin, while you shop for a better head unit.

At the risk of repeating myself, I'd suggest Dynavin if something like an OEM look is important.

If not, get a Sony or an Alpine, whichever fits these cars (I think it's the Sony).

maw

[Bimma360]

I have heard a lot on the forum that the Avin's do not sound good, but honestly that hasn't been my experience. I got one for my e53 4.8is back in 2019, and did not notice a change in sound vs stock. OP, I got a an Avon for the e46 (with the upgraded DSP chipset) as well and funny enough with the bavsound speakers too. Haven't installed it yet though. I have no illusions that these are Chinese units that at best could be the luck of the draw of what you get unfortunately. Hoping its not the unit on your end.

[Obioban]

I do think the Avin's are particularly crap. I had two of them fail out pretty quickly. Moved to the XTrons a couple of years ago, which is also chineseium, but it's been solid for several years now-- zero complaints with it.

[Shonky]

To prove its the Avin 100% you could depin and swap left and right outputs.

Are you sure it's not the BM5x radio amp module. It still is used in line before the HK amp.

[Mayan-Viking]

Shonky that's a valid point. Thank you. I didn't think about the BM5x radio amp module. Is that the silver thing in front of the amp in the trunk? I wasn't sure if there was anything else inline in the circuit...

If it's not that it would pretty much have to be the head unit, correct?

[Shonky]

BM53/BM54 hybrid amplifier ICs are notorious for dying.

Note however at that point there are only four channels - front and rear, left and right. In the HK system it just takes these 4 channels and splits and amplifies them internally so there's 10 separate amplified channels internally. If the noise is only in one driver in the door and not the other speakers created from that channel then it really points more to the HK amp (but you've replaced that), wiring from there or the driver itself (also replaced). It's possible the noise is only lower frequencies so may not really be heard on the other channels.

Or do you have the old head unit you could try perhaps?

Random photo I found. On the left of the coupe trunk, below the navigation computer and CD changer if you have them. Behind the TV module and in a HK system I think the HK amp is behind it from memory. If you replaced the amp, I'm pretty sure you would have had it out. It has BM53 or BM54 on the label:

[amiao]

Interesting comments, I’ve got the Avin 4 head unit as well as Bavsound speakers and I’ve never had an issue with sound quality. Currently running a Roxford Fosgate amp to pair with a 10” Alpine subwoofer. The only issues I’ve run into with the Avin is connecting car play (sometime fails connection & requires restart of iPhone). There’s a 2-3 second delay in music play/sound. And lastly I have never figured out how to get the I-bus app to work.

[Mayan-Viking]

Shonky I see what you are saying, maybe the entire right side is bad but only presents on lower frequencies and the door driver by default. Thanks much for that. Very good idea. Just ordered a used BM53 unit on eBay, hopefully this will be my issue. If not then I will replace the head unit and see if that fixes it. Thanks again!

[WestBankM4]

Interesting comments, I’ve got the Avin 4 head unit as well as Bavsound speakers and I’ve never had an issue with sound quality. Currently running a Roxford Fosgate amp to pair with a 10” Alpine subwoofer. The only issues I’ve run into with the Avin is connecting car play (sometime fails connection & requires restart of iPhone). There’s a 2-3 second delay in music play/sound. And lastly I have never figured out how to get the I-bus app to work.

Did you run your Rockford Fosgate Amp to your headunit?

[Mayan-Viking]

So I've now replaced the HK amp and the BM53 amp and the distortion on the right door driver still persists. I guess at this point I have to assume it's the head unit. But I hate assuming. Is there anything else I might be missing? I know I can put the old unit back in and test it but want to be sure I have addressed all possibilities before I go down that route...