Sound Deadening - CCF/MLV Passenger Rear Wheel Well

[JWebb_C7_Comp]

Hey guys,

I've made a little progress on my sound deadening project. Specifically, I've "wrapped" my passenger wheel well with CCF stuck to MLV. MLV faces out; CCF faces existing, stock foam padding. Ultimately, I used (6) pieces of the combined CCF/MLV. Two approximately triangular shaped pieces reach up into the "outside portion of the wheel well. The first is narrow and reaches nearly to the point where the fuel door attaches. It is stuck at the top to the metal via velcro. The next piece overlaps a portion of the first one, but extends downward toward the fuse box area. That pice has velcro, and it is connected to another piece that straddles the divide between sides of the wheel well. It is also connected to a piece on the interior side of the wheel well. I have one large piece on the interior side of the wheel well and two stacked somewhat similar to the way in which I stacked the outside pieces.

Take a look and offer any comments - good, bad....etc.

Also, note that with summer tires, my avg. dB measurements have declined slightly (just less than 1 dB - from 62.4 to 61.5). That said, I have also placed MLV over the carpet in the trunk and I have stuffed HMF into the holes on the bottom side of the speaker deck and into the void behind the passenger seat side bolster (which has almost zero insulation/deadening material).

My general observations are that (1) the "wind" noise from the rear is much less discernible, making the project worth the time I've invested and that (2) I can now hear my engine and front tires more than I previously could. Go figure; I'm not focused on that noise from the rear.

Next, I'll remove the speaker deck and properly finished it with a combination of CLD (Dynamat Extreme), HMF, CCF and, where appropriate, MLV. I'll also do the driver side wheel well and rear seat side bolster. It will be interested to see if I get another dB in noise reduction with that -- somehow, I'd bet I'll see diminishing returns, however.

Once this nonsense is done, the sub will go in.

[S4Per]

Cool to see you continuing to move ahead, but sorry to say that I don't think that will get you optimal results.

The key to MLV is to not have holes or gaps between the pieces where air/sound can get through, hence why you see a lot less tidy install of it on mine (and others) - - note all of the strips used to act as seams between larger pieces.



Best as I can tell from your photo I don't think you addressed that. I'd recommend iterating on what you have there.

[Audibot]

This sounds like something I should do over the summer once I'm back from vacation. Did it on my B7 (helped reduced the drone), and still have leftover butyl and ccf.

This'll work to sub me.

[JWebb_C7_Comp]

Cool to see you continuing to move ahead, but sorry to say that I don't think that will get you optimal results.

The key to MLV is to not have holes or gaps between the pieces where air/sound can get through, hence why you see a lot less tidy install of it on mine (and others) - - note all of the strips used to act as seams between larger pieces.



Best as I can tell from your photo I don't think you addressed that. I'd recommend iterating on what you have there.

Thanks for the comments!

So, by using Velcro and overlapping, I’m still allowing airflow; and, as a result, the damned sound waves get through? My working theory was that with overlapping layers held by Velcro, I’d have 100% coverage, but I get that air could twist, turn, and travel.

If i pull up what I have, how do the wire harnesses come of their posts; can I pry off and replace, or do they break off?

Permanently attaching what I have with a bit of MLV and H-66 would be NO problem but for accessing wires at a later date..

Also, am I correct that HMF blocks higher noises, but not lower frequencies where tires and exhaust would be?

For what it’s worth, I got 2X2 of the HMF, and it’s easy to work with and does not burn! I held BBQ lighter to the product from SDSD for 10 seconds 3 separate times. NO fire. That Don guy has some nice stuff. I just gotta learn how to best use it.

Thanks for the help.





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[Phantom75]

I really want to do this, but I don't want my car to gain a bunch of weight haha!

[OlyS6]

Hey guys,

I've made a little progress on my sound deadening project. Specifically, I've "wrapped" my passenger wheel well with CCF stuck to MLV. MLV faces out; CCF faces existing, stock foam padding. Ultimately, I used (6) pieces of the combined CCF/MLV. Two approximately triangular shaped pieces reach up into the "outside portion of the wheel well. The first is narrow and reaches nearly to the point where the fuel door attaches. It is stuck at the top to the metal via velcro. The next piece overlaps a portion of the first one, but extends downward toward the fuse box area. That pice has velcro, and it is connected to another piece that straddles the divide between sides of the wheel well. It is also connected to a piece on the interior side of the wheel well. I have one large piece on the interior side of the wheel well and two stacked somewhat similar to the way in which I stacked the outside pieces.

Take a look and offer any comments - good, bad....etc.

Also, note that with summer tires, my avg. dB measurements have declined slightly (just less than 1 dB - from 62.4 to 61.5). That said, I have also placed MLV over the carpet in the trunk and I have stuffed HMF into the holes on the bottom side of the speaker deck and into the void behind the passenger seat side bolster (which has almost zero insulation/deadening material).

My general observations are that (1) the "wind" noise from the rear is much less discernible, making the project worth the time I've invested and that (2) I can now hear my engine and front tires more than I previously could. Go figure; I'm not focused on that noise from the rear.

Next, I'll remove the speaker deck and properly finished it with a combination of CLD (Dynamat Extreme), HMF, CCF and, where appropriate, MLV. I'll also do the driver side wheel well and rear seat side bolster. It will be interested to see if I get another dB in noise reduction with that -- somehow, I'd bet I'll see diminishing returns, however.

Once this nonsense is done, the sub will go in.

Looks pretty good- do you plan on gluing down the overlapping edges?

Did you use any CLD underneath the OEM foam ot the wheel wells?

[JWebb_C7_Comp]

Looks pretty good- do you plan on gluing down the overlapping edges?

Did you use any CLD underneath the OEM foam ot the wheel wells?

Hey OlyS6, I hope you get some time to start your project. It would be good to read your observations as well. To answer your questions, I did not add any CLD on the wheel wells underneath the factory foam insulation. The car seemed to have a good amount of a factory applied constraint and it didn't seem hollow or sound like a tin can. The same could not be said about the floor under the spare. Hence, I covered a good deal of that real estate along with some of the rear quarter panels. I hadn't planned to glue down the pieces I stitched together with overlapping layers & Velcro. Having read S4per's comments, I'm re-thinking that plan. At a minimum, I'll figure out how to remove the factory wire harness on the driver's side when I get around to doing that side; and, I'll glue that side together as shown by S4per.

All that said, the car is at about 64 dB when cruising in low 70s on decent pavement and the irritating noise from the passenger rear seems to be in check after the steps I've already taken. What's interesting is how I'm now more aware of front tire and engine sound rather than sound from the rear. So, certainly, the rear has improved slightly even if not as good as it can be done. I suspect that has more to do with treatment of the deck than anything else, however.

[elptxjc]

Hey guys, a little detour from the subject, but semi-related. The last rattle I have on my car quiets down when pressing on the speaker grille that is right below the door handle used to close the door from the inside. It sits over alcantara, so not sure what exactly is rattling, but maybe the speaker, as my buddy BigTex suggested. Need to get in there to investigate. Hopefully it just pries out, but didn't want to try without knowing it pops out, since I could break it if it's fastened from the inside, like it's typically the case. Hopefully somebody knows, so I don't have to start a new thread. Thanks.

[S4Per]

It just pries out.


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