How to Improve OE Sub Bass Quality and Eliminate Vibrations

[Stvee]

For those of you having issues with the drivers side subwoofer distorting....Do you have ASD (Active Sound Design) disabled? And if so how (physically unplugged ASD module or shut off using Bimmercode)...IIRC, the over-riding synthesized signal from the ASD module is only fed to the driver's side subwoofer...

Yes it's disabled via coding for me. The issue also persists whether the car is running or not.

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[roddrsw]

Yes it's disabled via coding for me. The issue also persists whether the car is running or not.

Same for me

 

[Stvee]

Same for me

New subwoofer made no difference. Unplugging the ASD module made no difference. I have that whole side of the car torn apart at the moment and I still can't find where it's coming from.

I guess the next step is to take the rear cross bar out. I need to go buy a T50 though.

Edit: I took the crossbar off on the drivers side and couldn't tell a difference. Starting to run out of ideas.

 

[roddrsw]

New subwoofer made no difference. Unplugging the ASD module made no difference. I have that whole side of the car torn apart at the moment and I still can't find where it's coming from.

I guess the next step is to take the rear cross bar out. I need to go buy a T50 though.

Edit: I took the crossbar off on the drivers side and couldn't tell a difference. Starting to run out of ideas.

Oh crap....

Where you able to see underneath the subwoofer? Maybe removing it from the box and see if there's still noise?

 

[ShakaDaKine]

Oh crap....

Where you able to see underneath the subwoofer? Maybe removing it from the box and see if there's still noise?

Since you have all the panels out, you should check the output from the Amp on that channel. Is your subwoofer jumping up and down (clipping)?

 

[Stvee]

I did some more testing and took the subwoofer driver out of the box while it was playing so it couldn't vibrate anything and the sound is 100% coming from the driver itself.

At this point either both my original subwoofer and the one I bought are blown or there is something else going on.

Any ideas @tadda ?

 

[tadda]

I did some more testing and took the subwoofer driver out of the box while it was playing so it couldn't vibrate anything and the sound is 100% coming from the driver itself.

At this point either both my original subwoofer and the one I bought are blown or there is something else going on.

Any ideas @tadda ?

If it's low bass distortion you're hearing and you replaced the sub and it still does produces distortion, then it's coming from the Amp....

 

[Stvee]

If it's low bass distortion you're hearing and you replaced the sub and it still does produces distortion, then it's coming from the Amp....

Unless both subs were bad. It was a used one off ebay.

I guess I need to take the other side of the car apart and swap speaker from side to side next.

 

[tadda]

Unless both subs were bad. It was a used one off ebay.

I guess I need to take the other side of the car apart and swap speaker from side to side next.

I assumed you already did this....Good luck...

 

[Stvee]

After swapping speakers, the drivers side always sounds worse regardless of speakers but neither are great. This is making me think the amp might be messed up.

 

[Sam B]

You definitely have a bigger issue at play here. Definitely an amp issue of some sort

 

[Stvee]

I'm taking it to the dealer tomorrow with the interior already taken out so they can easily see what I'm talking about or swap speakers for themselves if needed.

BMW has had some issues with amps in recent years so it wouldn't be too surprising. Just bad luck.

 

[Stvee]

Dealership agrees there is definitely something messed up since the distortion is extremely easy to hear with only the subwoofers playing any sound. I explained all of my troubleshooting steps and why I think it's probably the amp at this point.

They took a video with the balance all the way to one side and then the other and you can clearly hear the driver side distorting. Now I just have to wait to see if Toyota corporate approves the amp replacement.

 

[Stvee]

Surprisingly replacing the amp did not fix the issue. They're going to try a software update next.

If it's not that it has to be the head unit or wiring I guess.

Edit: No luck on the update. They're waiting for a response from Toyota at the moment.

 

[Sam B]

Wow. Sorry to hear this. That’s definitely a shock. I figured it was definitely amp related.

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