I moaned here a couple of months ago about the really obnoxious noise intrusion into my '06 DB9 Volante while driving on a multi-lane concrete highway with the top closed. The biggest issue was semi-trucks' tire noise, which was right at my wife's and my ear level.
I decided to buy some SecondSkin automobile noise control products, and I went out today after having installed some treatment in just the doors of the DB9 so far.
Oh, my goodness...
All I've done to this point is install their Damplifier Pro sound deadener and some Luxury Liner Pro barrier in the doors. The Damplifier Pro is an elastomeric butyl compound with a very heavy foil backing (feels like thin aluminum sheet). It's self-adhesive, and best applied with a small wooden roller to ensure that it fully mates to the inside of the door skin. I removed the inner door cards and - after checking that the windows had enough clearance when they're lowered - cut pieces to cover as much of the inside of the outer door skin as I could access, then used a wooden roller and a range of pry tools to smoosh it firmly in place.
There's an amoeba-like cutout in the inner aluminum door panel with a weather strip/gasket around it that conveniently leaves a mark on the inner (roadside) face of the door card (the leather-covered panel with the inside door handle, etc.). I cut a piece of SecondSkin's Luxury Liner Pro to fit that cutout and glued it to the door card's inner plastic face, effectively closing off the cutout, but leaving plenty of room for the window motor. Luxury Liner Pro is a dense, closed-cell foam with an outer mass-loaded vinyl layer, and its job is to be a barrier to sound intrusion.
After reassembling the doors, I went for a drive, but stopped in my driveway to make sure there wasn't something wrong with my car. It sounded very different in the passenger compartment with the top up, and I wasn't used to the noises I was hearing. My belts sounded different. My exhaust sounded different (less reverberant). My valves sounded different! I made it a hundred yards down the road and stopped again, got out, and looked under the car!
It's weird how familiar we become with how our cars sound, and while my intellect knew that the SecondSkin products were the only change, my emotions had a hard time accepting that there wasn't anything else going on.
I have a Grom USB and Bluetooth audio module installed, and I turned on the stereo (the 900w Linn). It was immediately clear that music sounded different, too. The bass sounded tighter and the upper frequencies had more sheen and zing. And that was with just the doors treated.
So, I did the doors first because they were easiest. I hate removing the wheel well liners, but that's next. I think they act like a big microphone diaphragm and capture a lot of road noise. I plan to add some of the Damplifier Pro to their back sides to try to deaden them, and I may add some of the Luxury Liner Pro where I see some cavities. When I get around to it, I'll pull up some carpet and add some of whatever I have left to the floor.
The change I've experienced so far isn't the result of some kind of expectation bias; I didn't expect much difference, and it caught me by surprise. And yes, the exhaust still sounds great, even inside the car!

 

That's pretty awesome. Road noise is such a killer for a relaxing drive that doesn't fatigue you over a distance. Sounds like a great improvement!

 

Thanks for posting this. I have always been underwhelmed how the doors sound "cheap" when you close them. I suspect adding this helped with that as well.

 

I suspect our cars are quite similar...mine's #4899. Of course, while I've done a ton of standard maintenance and "little" jobs, I've never tackled a project like yours!

 

Thank you for the write up! I never even considered something like this for deadening some of the typical road noise we deal with. Great idea!

 

Major noise intrusion on my 07 V8V seems to eminate from harshness at the 4corners, wheel/tire assemblies and suspension. Has anyone been successful with application of Second Skin or other products to the injection molded wheel house liners? How about Member Zuman, do you have an update on your DB9 application?