Meatball964

klokwerk

Not too long ago I tore out all of my old rubber sound dampers and carpet. I used Dynamat Extreme with great results. RS carpet over the top of it works great.
Take your time and it's an easy job.

Deserion

LPMM

Goughary

Sound deadening requires absorption of vibration- resonance frequency - and sound absorption - which is handled well by the oem foam and the tar like material...

In the stereo world - this is done effectively through constrained layer dampening - so the use of materials that resonate at different frequencies so the initial vibrations are changed and blocked and deadened as they travel through the material. So- for a wall, as example, you can use layers of different types of wood, with sheets of aluminum and gypsum board mixed in, and then foam on the outside, that kill all the noise. If you go too far, you can make a chamber that feels very strange to be in, because your brain doesn't like "zero" sound.

Macintosh has an anechoic chamber in their lab in Binghamton, Ny where they test speakers that's very disorienting.

In a car- it's very complex, because we have weight and space constraints. And so it becomes about compromise. How much noise, and what type of noise, etc. Aka, drone sucks.
And it also sucks to not be able to talk on the phone because the microphone is picking up all the noise and cutting everything off...lol.

I've been thinking about this a lot lately, as we will be doing a weight saving program on the Alabama car once it gets back from getting its new motor, and it's going to be loud. But we want to remove the heavy oem sound deadening and attempt to lessen the noise where it's necessary.

So the questions become- where is the source...and then deaden first, vibration from those areas, and then absorb the sound waves traveling through the cabin.

Should be fun- so i hope some sound experts will chime in here. We have to have some audiophiles that have worked on cutting noise in a 911 around.

Fwiw- the one thing i haven't worked out yet- is the main source of loud cabin noise and drone- which is the vibration and sound that travels up the c pillars to the roof. The roof on a coupe acts as a speaker and clobbers your ears. Targa and cab don't have this problem and can be much more pleasant to drive in as a result.

VW bugs had a molded foam piece that got stuffed up into the c pillar from the bottom for this reason.

Downside to our problem. Is that there is no real sound deadening solution that isn't heavy. So my question and what i will attempt to explore is how to take out weight and use a good set of contemporary materials in just the right places, to take the sound down, but still lose weight.

Has to be possible.

Spyerx

golfnutintib

i too did dynamat on the floorboards, trans tunnel and rear seat areas once car was stripped ... unlike chris i did not remove sunroof so my roof/lining is stock

car is loud but not boomy, mostly clatter from lwfw at lower speeds, lovely engine sounds at pace

Achtung964

Are you guys doing the work yourselves? Removing the sound deadening material and glue seems like a daunting task. Also seems like it would be days of billable hours to outsource. Curious how you'll handled it as this is in my near future.

GoatFarmer

I have not removed the sound deadening and glue from my 964, but I have done so with my M3 of the same vintage. It is very easy to do. Using gasoline makes quick work of the glue.

Goughary

Wd40, a hairdryer and plastic knives for the glue

cobalt

Use lots of safety equipment in a well ventilated room. A gallon ofXylene straight out of the can onto microfiber cloths let soak and wipe away nothing works better. I did my entire interior in under two hours.

I used a small amount of dynamat in the center of my roof which took care of the vibrations covered it with alcantara with foam backing

porsche mania

my top tip, don't wear shorts. Unless you like waxing your legs at the same time! Took me 2 days to do mine, most of it was easy, any glue near oil pipes/tanks was I nightmare as it's baked on! Laying a rag soaked in your solvent of choice over the area you plan to do next got it softened then it's just elbow grease with a rag. Wish I'd seen the plastic blades before I did mine as they look like they would really help with the baked on bits. Get stuck in, it's really not worth paying someone else to do!

porsche mania

what did you use to get the floor flat after ditching the oe foam? Mine has crumbled and really needs sorting but I want my mats to lay nice and flat.

spartansix

I have the same question.

The floorboard has a big rib down the center, so even with dynamat and carpet it won't be flat.

Goughary

My idea for that area was to use dynamat in 6 inch squares. On the floor, and then light weight sound foam in the cavity, and then make a floor board with a light wood with carpet glued on one side and a layer of vibration deadening on the other- constrained layer dampening- and then mount that board firmly to the floor- keeping it removable- would be light and effective for road noise.