Has anyone deadened (dynamat, for example) the floor of their 997.1 TT? I am looking at doing an install of an Alpine INE-S920HD and full deadening of the floor (front footwells to back seats) of the car. I'm hoping it will make a significant difference for overall highway road noise.

 

I'm all ears on this one.

 

I'm guessing that the rear wheel wells may actually make more difference. This and the area behind the back seats have always been large contributors to cabin noise from my experience with hatchbacks... (and this isn't a hatchback per se, but it does have a large open area under the back glass to reflect sound forward)

 

These are good points kitw

I'd love to hear from someone who has sound deadened their 911, and can speak to the results.

 

Tuned into this one. I would love to quiet my cabin a bit.

 

Well. I've decided to pull the trigger, so I'll be the guinea pig! CarTunes Atlanta is putting 35+ sqft of deadening in my 997TT along with the full Alpine head unit. I'll report back on how everything looks (and sounds!) when done in a couple of days.

 

Dear Trevor

Subscribing ;-)

 

I put in some sound deadening under the rear wheel wells and rear cargo area while chasing down some cabin noises. The noise turned out to be a failed bearing on the water pump oddly, crazy how noises can sound inside the car!

The stock stuff in the wells is flimsy but I still did not notice a difference at all. It was a huge difference going from Pirellis to Super Sports though road noise wise.

With no improvement I removed it all after a few weeks. Not a fun job either first time around.

I did notice the bass was a bit boomier though, not in a good way either.

 

What was the material you used for sound deadening?

 

Could you also have them weigh the materials before they put them in? Also, decibel meters are very inexpensive.... You will have a lot of friends on here if you measure noise at idle and cruising speed before and after the install.

 

There's even an App for that ;-)

 

I have used dynamat and carpert pad on a few of my older euro and american cars=it helped but not day and night difference.Hope this helps?

 

If it was me being a car audio expert for the past 13 years, I would recommend doing 2 layers of Dynamat. First layer go with the Dynamat extreme. The key in to do the doors, inside and out, floor behind the rear seat and rear wheel wells because it a mid engine car under the seats and the foot well. the second layer use the Super light and do the whole floor and back seat fender areas as well as the roof if it is not a convertible. 2 bulk packs of each should do it. you will add about 100 lbs in material. I stock the material i can give you a whole sale deal plus shipping message me. you will get about a 10db reduction in road noise in the car on average.

Heres a shot of a 991 Dynamat

 

I used Vinyl/Nitrile foam and some cld tiles.

 

I used Dynamat Extreme all over my 996 TT. Rear deck, under the seats, console... Took lots of time and added lots of weight. To my surprise afterwards when I took a drive, I really couldn't tell the difference at all. If you need a decibel meter to see the difference, it's probably not worth the effort.