400 Shows. Hell yeah. My wife makes fun of me for both the love of my P car and my love of the boys. Good luck with the sound Deadening.

not sure of the individual brand names but most likely it was an ensolite-based product.

Found it...
SUPER SOUND PROOF WITH ADHESIVE from Aircraft Spruce

Wow, this stuff sounds interesting. What thickness did you use?

Nineball.....Ever use this, is it comparable to what you use now?

You guys are a great source of info.
Thanks to all!

Actually lost count at around 400! Still got ticket stubs for most of them. Me and my girlfriend followed them from town to town in a 66 VW bus back in the late 60s - 70s. Different world then. Still listen to them on XM and Dicks Picks....just not as much VOLUME!

i have never used that before but it is a closed cell foam product. everything i have ever read says that open cell foam is much better for blocking unwanted noise. i read their installation pdf and it calls for a minimum of 2" of their product which is somewhat easy to do in an airplane but it would make it practically impossible in a car. i am not saying it doesn't do the job but it just goes against everything i have ever read on the subject. i am by no means an expert, this is just a field that is related to my 20+ year hobby.


i just realized what you guys were talking about (400 shows). spent the summers of 92-95 on the road myself including my last show ever at 3 rivers stadium. rusted root opened and at the time i had never heard of them but it was a nice little extra treat. before that is was just whenever i could afford the time off from work.

Not trying to contradict you nineball but didn't someone post on one of the other "noise elimination" threads that Porsche is using a closed cell type of insulation under the carpets in the newer 911s?

could be :) like i said i am no expert i am just going off of what i have read over the years.

I've learned a lot reading everyone's posts regarding noise/sound reduction (nineballs included). I think the older 911s can certainly be made quieter but they will always be a noisier beast compared to newer cars.

I used 3 different thicknesses, but should have just used one due to the sizes it came in, roll wise. I had to piece together some of it because the dif. size rolls did not provide enough coverage. The thickest I used was 3\4 inch and by no means did this stuff make my car sound proof as that wasn't what I was after. Since the RS carpet is pretty thin, I wanted the carpet to have a somewhat smooth surface for it to lie on, and this provided that along with some sound deadening. Also, I only used it on the rear.

i could be totally wrong with the info i have, it has been known to happen once or twice in my lifetime :) i sent an email to ssa asking them to explain the differences and benefits of ccf vs ocf. i'll post up what ant (owner) tells me.

Just to make it a little more clear....I don't want to turn the 911 into a Lexus, just "Deaden" the vibrations/noise coming from the rear. I removed the radio & speakers so insulating it for optimum tunes is not a factor.

well... to do it right it is at least a 2 stage solution. you need something like dynamat xtreme or damplifier / damp pro to stop the metal panels from vibrating and causing excess noise, but those products are not designed to block noise. you need something else for that. my suggestion to you would be to go with a butyl-based product like those mentioned above first and see how you like the results. if you are happy with the results then you can stop there. if not then proceed to the next step.

I used Quiet Coat after cleaning all the old sound deadening off. It turned out good with no problem installing the carpet. Its a brush on or spray on liquid.
Its been 2 years with no problems.

well i know why this is a hobby and not a career for me :) turns out i was wrong and closed cell is better for reflecting sound, open cell is better at absorbing. you really do learn something new every day. here is the response i got from the owner of ssa.

Closed cell foam is better for blocking out noise, but open celled foam is better for dissipating noise. Many engineers will debate this issue as it is frequency dependant. Personally, the only time foam should be used in a car is if it is a gasket material or if it is being used as a decoupler with a mass loaded vinyl.

Foam by itself is a terrible material to reduce noise. It hardly does anything unless it is applied very thick. In a car, you can not apply it very thick so the results are very small. This is why the mass loaded vinyl is so much better. The mass that comes along with it is huge, so the results are much better.

For your car, the Luxury Liner Pro would be the best product to apply on top of the Damplifier Pro. The results will be amazing!

The foam on Lux Liner and LLP have more to do with the decoupling effect (raising and separating of the materials) than noise reduction. The foam elevates the vinyl off the panel which helps slow the sound down so the vinyl can block it. Foams by them selves (unless very thick) are pretty much a waste for blocking noise.. Well, low frequency noise any way. Upper range it works well but in a car there is very little of that.

Well, I *just* finished a little sound reduction project on my own 1980 SC. My plan was to remove the old sound mat on the interior behind the seats and replace with something new and more modern. I also wanted to check the parcel shelf area as this is a known area for rust. I didn't want to go beyond that, my carpet is in decent shape and I didn't want to rip that out at this time.

I met with the owner of Second Skin Audio (they're here in Phoenix) and he recommended Damplifier Pro with Luxury Liner Pro over that. This provided me with nearly the exact thickness as the original mat. The nice thing is that Damp Pro is now in a flat black finish so it doesn't look like you are constructing a moon lander. Sorry I did not take pictures as jhubs, nineball and others here have documented this all pretty well.

Good news - no rust back there. I did not weigh the pieces coming out and going in but the new stuff together is similar in weight if not a bit lighter. I ditched my (shot) rear speakers so I saved several pounds there.

After hitting the road with a careful ear I did not find a huge reduction in sound. It was small but as someone else mentioned, you may hear some of the other sounds a little bit better.

My next project was to replace the engine compartment sound mat. Mine was 30 years old but largely intact with some sags and unsightly. I used the new OEM lightweight pad. The install wasn't as bad as some people make it out to be for a CIS car. A four inch engine drop gave me the room I needed.

I hit the road again. Another *small* reduction in sound. Not what I was hoping for. My goal was to get nearly as quiet as my 1984 Carrera, there really is a noticeable difference between those two cars.

My car is a little bit quieter now but not enough for my wife to notice. The plus side is a tidier engine bay. I may try some Damplifier Pro in the doors, many have said that that does help with road noise.

Sorry for the long post and semi- hijack of this thread. I figure people doing interior work could make some use of it.

the doors would be good to do but i think you would achieve better results by taking up the carpeting and doing the floorpan and rear seats completely. i did the same area as you (see above pics) and the doors and really did not notice a large change in sound level even with putting the factory piece back on top of the newly covered parcel shelf. in the spring i plan on using damp pro and some llp over the floor and rear seats which should do quite a bit of reduction.

nineball,

I think the next thing I'll try is the doors and perhaps the floor. The rear seat bottom material looks to be the same as the parcel shelf padding and that old stuff was doing pretty well compared to what I just put in. I would like to know what changes they made to sound insulation (and where) in the 3.2 Carrera.

Kurt,
Your experience in 'small' sound reductions is what I would suspect. Based on my experience with vibration damping, I would really be suspect of CLD approaches. I understand CLD is not a noise absorber and it's sole purpose is to reduce panel vibrations and the resulting structural noise, such as 'drumming'. But as I described, it really is an engineered solution dependent on many variables. My opinion is that simply buying sheets of it and slapping it on various size panels will be hit-and-miss. Not to mention the cost! On the other hand, I can see the value in some of the noise absorbing mats discussed here.
I'm interested in this topic, and people's results, as I'm in the middle of restoring my 71T and I've been debating whether to put something new underneath my new carpets I will be installing.

I would tap each panel - if it sounds dead ---> no CLD there.

Otherwise, I would add a CLD material to the middle of the panel & continue towards the edge until I had covered 20-30% of the panel. test by tapping as you go.

Then add a layer of foam, felt or some more exotic material over the whole panel.

But FIRST, I'd seal any holes and fill any crevices with a ceramic micro-bead "liquid goop" material.

Anything that when magnified might resemble an old timey "horn" loudspeaker should be addressed. Is it obvious why?

Pretend you are an ant.