86 951 Driver

Lately I have been hearing more and more rattling from my doors. I have solved almost all of my rear hatch rattles, but not the doors. I want to take the door panels off and tighten everything down along with maybe add some sound proofing. Any experiences with installing dynamat or alternatives in the 944 doors?

V2Rocket

I put a small patch of dynamat in the doors behind the speakers, helped a bit. Am considering adding more or finding an alternative that is less expensive though.

86 951 Driver

Have you heard of Peel n Seal from home depot?

http://www.fitfreak.net/forums/2nd-g...deadening.html

http://volvospeed.com/vs_forum/index...r-peel-n-seal/

V2Rocket

Yes, but as those people talk about the smell is the killer. One of the reasons that Dynamat is so expensive is that it's not an asphalt-type material. I live in an area where temperatures can hit 110* in the summer so the smell would be awful.

I am considering using urethane like the transmission mount trick, or an expanding urethane foam instead.

kcoyle

There is some great info here and apparently fair pricing.

http://www.sounddeadenershowdown.com/cgi-bin/index.cgi

That said, I used some McMaster Carr part #9709T26 in my doors. (cheap) Tightening everything down helped a bit also.

V2Rocket

How'd that McMaster stuff work

peanut

https://www.youtube.com/watch?v=f5Qi2AMm7sI

Fitting sound deadening to your doors is not going to address noises from within your doors. The deadening material is fitted inside the door to the inside face of the outer panel not the inner side of your doors .

You need to fix whatever is loose and rattling inside your doors first.

biggest improvement you can make is to deaden the trunk/boot area. I simply lay a thick rubber-backed 928 original rear hatch carpet underneath my 944S2 rear hatch carpet and i cannot hear any road noise from the back now.

here is a good explanation about sound frequency sound absorbtion and sound reflection the difference between them and the use of various types of materials.

http://www.sounddeadenershowdown.com/cgi-bin/index.cgi

kcoyle

I can't really compare it to anything else as I've only used that product in my cars, but it does what it's supposed to do. It takes out the "tinny" sound of panels. (resonance) Its pretty easy to work with, doesn't stink, it sticks very well, and the price is right. I clean all panels with alcohol and stick on. I used a heat gun this time because it was 40 degrees in the garage. I added it since I was installing front speakers and already had the doors apart. I also tightened and greased everything that needed it. Some screws took a full turn or two.

KC

CurtP

Original Dynamat is asphalt based. I can tell you from experience in the FL heat, it stinks really bad too. Dynamat is overpriced and overhyped - there's cheaper, better deadeners out there. B-Quiet Ultimate works better than Dynamat's butyl-based Xtreme at less than half the cost.

I removed all the factory deadener and used B-Quiet Ultimate deadener with Second Skin Luxury Liner Pro barrier. If I was to do it again today, I'd probably use Second Skin Damplifier Pro deadener on the floors and tunnel and Damplifier on the doors and side panels. I would still use Luxury Liner Pro barrier on the floor and tunnel.

CyCloNe!

I'm actually about to buy some B-Quiet Ultimate, I've heard good things.

KuHL 951

I've used a Polyken foil-backed butyl rubber tape product used for roof flashing on 4 different cars and was always amazed at the results. It has no smell plus cuts heat gain through the tunnel area. One drawback is once you remove the release liner and put it down it will not come off no matter what you use short of nuclear intervention. Do not use anything with an asphalt based mastic or you will loath your car in hot weather. Do a search on sound deadening in the 944/951 forums, I posted info many years ago. The price is right and it requires no heat to bond. I've used a product called Nu-Prene (neoprene) behind the rear seats that worked excellent also.

Sound Deadening

OTOH if you are hearing the rattle in the drivers side door it could well be a common issue where the window guide channel spot-weld breaks. My 86 did this and it often results in a small visible sheet metal crack at the lower/outside corner of the window area. I drilled a very small hole where the weld breaks from inside and JB welded a screw instead; it worked great and was hidden behind the door card.

peanut

you need to understand the difference between sound absorbtion andsound deadening so that you know what you are trying to achieve and why.

Its worthless just banging in loads of proprietary treatment randomly around the car. you could make the situation worse , at the very least waste a lot of money.

Porsche spent $millions researching effective acoustic insulation in their cars its beyond me why owners think they can improve on Porsche technology by ripping it out and replacing it ?

this bloke spent years studying it and his explanation and conclusions make a lot of sense
http://www.sounddeadenershowdown.com/cgi-bin/index.cgi"]http://www.sounddeadenershowdown.com/cgi-bin/index.cgi[/URL]

JimV8

If the objective is to stop rattling then tighten loose stuff and then make the door opening is as airtight as possible. High pitch sound travels through air even patching tiny holes will do alot for attenuation and low pitch sound travels through structure setting up sympathetic vibration so isolation is key to reducing that.

marcoturbo

For people who have experienced door sound deadening, is the gap between the inner door and the panel wide enough to put a thin CCF foam sheet ?

Did you put the (white) plastic vapor barrier back ? If so, what is the order of the install ? door + plastic barrier + foam or door + foam + plastic barrier ?

I found the OEM door sound deadener in the PET (it's a 993... part number) and bought it. It's an asphalt based sheet but the guy who has painted my car didn't succeed in fitting it (it wasn't sticky enough to hold on the outer door without heating it a lot...).

There's also an OEM foam sound deadener in the rear fender in the trunk area (not in the insulation section of the PET). Does anyone know where it should be fitted ?

For the sound barrier, I consider buying a roll of heavy rubber. It's heavier than audio mats (I had second skin luxury liner pro as MLV before) but quite cheap. To stop sound, the mass is the key.