Sound deadening 1973

[JPM]

The other part of the sound proofing is the sound deadening pad that goes between the tar stuff on the floor and the carpets/floor mats. I know this was on my 73 T because I have pieces that were glued to the floor. Here is a picture of one from the back seat area:

I went to an upholstey supply store and got a roll of this carpet padding. Cut to shape and glued to the floor it looks like this:

Attachment 506527

Not sure if this is exactly correct, but I matched the original best I could. It will help cut down noise and make the floor carpeting more comfortable on my feet.

This must explain why I don't recall seeing a diamond texture on my floors. How thick is the carpet pad?

[RC70SCoupe]

Out of curiosity, what was the weight gain?

Not sure, the box was not heavy.
My motor is a 2.9 twinplug, MFI. Don’t notice any decrease in performance as a result...other than being in a quieter environment.

[Longballa]

Chuck, that material is called JUTE and I've never seen it used between the floor mat and the sound deadening on the floor. Ray, that's a lot of material!! Dynamat and materials like that dampen vibration where other materials lower sound passing through. Think of a drum head on an acoustic drum. If you put a quarter size piece of dynamat on the drum head it's going to cut down on the vibration significantly. Porsche used the tar type material where they wanted to dampen vibration and the JUTE and other sound deadening materials like in the back seat and parcel shelf areas.

[BOYER73S]

I second Scott, never seen that installed as original on a 72 or 73

[csbush]

Yea- I had never seen the carpet padding either. I guess someone must have added it later. It seemed like a good idea.

[TheTorch]

I recommend reading up on the difference between vibration dampening, sound blocking, and sound absorbing. Covering the entire interior in dampening pads (butyl type like 3M or Dynomat) is a waste of money, time and weight.

Adding any one of them will certainly be an improvement from the jute / tar that was in there, but there is big difference between putting dynomat/3M everywhere vs selective dampening + sound absorbant + MLV on top.

It's a lot more work, but the results are far superior and can fit under stock carpet, shelf, quarters and seats:

[Peanut]

Can you (TheTorch) elaborate on what you used in your car? Where you applied sound blocking/absorbing material and where you placed vibration dampening? I cannot really tell from the picture, as the material all looks the same.

Thanks,

Scott

[TheTorch]

Can you (TheTorch) elaborate on what you used in your car? Where you applied sound blocking/absorbing material and where you placed vibration dampening? I cannot really tell from the picture, as the material all looks the same.

Thanks,

Scott

Damplifier Pro
Luxury Liner Pro (LLP)
Dynaliner

I first put vibration dampening (Damplifier Pro, similar to Dynamat) on the larger flat parts of everything: rear shelf and wall, rear seat, rear quarters, under the front seats. About 25% coverage. My doors already had factory dampening by the way. Old but still stuck on there.

Luxury Liner Pro (LLP) has MLV (Mass Loaded Vinyl) with closed cell foam bonded to it underneath.

What you see in the photo is the MLV. The closed cell foam is underneath MLV. The MLV outer skin is the last layer before the carpet. Because the vinyl has stiff edges and the LLP is fairly thick, the transitions take some care. Easing the edges at an angle, and putting 1/8" and 1/4" foam (Dynaliner e.g.) helps all the transitions of the gaps and angles, which keeps the carpet smooth. If you look at my photo above, pretty much all you see is the LLP, except on the radius of the tunnel, by the shift linkage opening. You cannot bend the LLP around a sharp curve. So that's where the Dynaliner is used. I also used it on the inside door sills, as I did not think I could build that up with LLP and still fit the carpet properly around the sills and seat mounts. You can see it clearly around the shift tunnel in the photo below.

The floors under the seats are super easy -- one large LLP the whole length on top of the Damplifier Pro but under the carpet.

[Peanut]

Thank you for that thorough explanation. Does appear to be a very thoughtful approach.

Scott

[NorthernThrux]

Thank you for that thorough explanation. Does appear to be a very thoughtful approach.

Scott

Yeah, if I wasn't a stickler for trying to emulate the original finishes, this is what I would do. Would make for a very pleasant cabin. I did something similar in my Audi RS4 when I replaced the Bose head unit and customized the audio years ago.

Ravi