Sound proofing to reduce road noise

**Glossy McGlosserton** · 02-27-2008, 12:27 AM

Here`s the link to the car audio article that sassuki refers to: Installing Dynamat - Sound Dampening Installation Guide - Car Audio and Electronics Magazine

Good photos and write up. And it sure does blame spray-on noise deadener for internal rust.

For even better photos and how-to with mat and roll foam, check out the Raammat site.

**paul34** · 02-27-2008, 02:56 AM

Indeed, this is a question of mine, too. Here is what I`ve found from those "half-baked" threads you probably also read:

*Sound proofing (such as eDead, which is a proven and cheaper alternative to Dynamat) is often used for general sound proofing used to reduce noise loss from the speakers - thus improving the audio in general in a car - and not so much road noise.

*The best way to dampen road noise is to use carpet padding and not the sound deadening material

I`m not sure how true this is. And yes, the added weight is a HUGE factor for me - I really don`t want to add more than 50 lbs, if that. Even 50 lbs would make a negative large factor in my car.

But with the amount of time I spend on the highway, some way of really quieting the interior would be nice. Yes, quieter tires will be good, but really, it does go beyond just the tires (at least for me).

**kpounds** · 02-27-2008, 07:53 AM

If you`re looking for a very quiet, smooth riding tire check out any of the Kumho`s at TireRack if one will fit your car. I have the Kumho Solus KR21 on my pickup truck. Its a smoooth riding quiet tire rated at 85,000 miles, and the price is right. Its a newer model Kumho, about a year old and is rated #1 in its category at TR. Honestly, mine are a bit softer in the turns compared to my old Firestones but for north-south cruising they are quiet and nice riding.

One other important point - Kuhmo`s are always one-size smaller than the label says. So if you need 195/75/13`s -- get 205/75/13`s. Its an oddity but true, and others will mention it in the TR reviews.

Another idea and yes, this is amateurish but it helped out was I bought some canned rubberized undercoating sealant and sprayed it underneath my truck and under the driver & passengers area and behind the engine compartment (low areas) where it couldnt be seen. I thought it did fairly well to reduce noise....although it was a bit messy and the idea of rubberized spray on your underbody might not be appealing - but I did get tangible results.

**Glossy McGlosserton** · 02-28-2008, 07:17 PM

A report back on the yoga mat (PVC dense sponge mat) used in the A-pillars. I really like the change. I think that the hollow pillars were carrying quite a bit of road noise into the cabin, because the road noise seems diminished. In a prior post, I described cutting yoga mat to fit behind the A-pillar plastic trim as a sort of full-face gasket between the metal of the pillars and the hard trim.

I`m thinking that dense sponge matting like this--which isn`t heavy compared to Dynamat Extreme and similar products--may be a good combination of sound barrier and vibration absorber. It decouples one vibrating surface from the interior surfaces.

I wonder how it would do under carpet for road noise? Sheesh, but getting the carpet up requires removing a lot of trim, and even the seats to do a thorough job.

Anyone have ideas about wheel wells? I`m thinking the bulkhead between the passenger and engine compartments and the wheel wells are very poorly insulated from noise and vibration transfer.

**bigltc** · 02-29-2008, 05:08 PM

check out Sound Deadening Materials for Noise Reduction from Second Skin

**Glossy McGlosserton** · 03-03-2008, 11:39 AM

Second Skin and Raammat seem to be the concensus choices for quality materials at a much, much lower price than Dynamat Extreme. Both carry products that are full butyl materials with no asphalt. Below is a summary of info I`ve gathered from lurking on various boards.

Second Skin Damplifier has an adhesive that can be repositioned if only lightly applied, and then sticks very well once tamped or rolled into final position. It has a relatively thick aluminum foil constraining layer. This may be helpful in vibration control. It is also a bit tougher on the hands during cutting and installation. Second Skin also carries various other sound barrier and absorption mats. The owner, Anthony (ANT), is said to be really helpful. Look on caraudioforum.com, caraudio.com, toyotanation.com, yotatech.com for news of discounts for forum members. These discounts may be old info, as ANT now has his own forum on his website, and membership provides a discount. Sound Deadening Materials for Noise Reduction from Second Skin

Raamaudio is likewise owned by a fellow said to be very personable and helpful. While Second Skin offers a range of materials, Rick McCallum at Raamaudio keeps it simple with two main products: raammat and ensolite closed cell foam sheeting. Prices are excellent. Raammat is a butyl mat of the same thickness as Damplifier`s main product, but the foil is thinner and has a poly film above and below it. People having used it say it is easier on the hands and easier to cut, but it is unclear if there is any effect on vibration constraint. Also, the adhesive really grabs, so take care not to touch it to a position that is not its final home. RAAMaudio - Quality and Value in Automotive Sound Deadening

**paul34** · 03-03-2008, 11:02 PM

eDead from Elemental Designs is also a very popular Dynamat alternative and the guys from ED are known to be extremely helpful. They also have their own forums as well.

**Glossy McGlosserton** · 03-08-2008, 11:12 PM

There have been some posts saying that eDead`s matting fell off vertical surfaces in summer heat. This may be an older version of the material. Also see the sound deadener shootout, for which the url is provided earlier in this string.

If they have brought out a new version of the product that doesn`t have the adhesion problems, this could be a really cost-effective way to go.

**thump_rrr** · 03-12-2008, 03:46 AM

If you are keeping your car long term make the investment and go with Dynamat Extreme.

You`ll be glad that you did.

I didn`t insulate mine to enhance the audio since I rarely turn on the stereo in my car.

I did it for the sound deadening properties and there is a definite difference.

**Glossy McGlosserton** · 03-12-2008, 10:52 AM

Thump rrr

Want to post more pics of your process, and what you observe as the result?

In particular, I`d be interested in what you found difficult, what you found easy, and what seemed to make the most difference, if you did things incrementally.

Personally, I`m intimidated by the thought of ripping out my entire interior. How long did that take you?

**thump_rrr** · 03-12-2008, 04:54 PM

Originally Posted by Sherri Zann

Thump rrr

Want to post more pics of your process, and what you observe as the result?

In particular, I`d be interested in what you found difficult, what you found easy, and what seemed to make the most difference, if you did things incrementally.

Personally, I`m intimidated by the thought of ripping out my entire interior. How long did that take you?

I actually didn`t take anymore pictures I only took that one because someone thought I was B.S.ing them that I had the interior torn out of the car.

Removing the interior took about 2 hours in total including the center console and center stack.

I took my time over 2 evenings and completed the whole floor from firewall to under the rear seats. I really underestimated how much material was required.

There is nothing difficult about it if you do it thoughtfully.

Most interior trim pieces on modern cars don`t even have any fastners in them.

I probably removed 30 screws and bolts in total including the seats and seatbelt anchors.

The rear seat comes out in 20 seconds and weighs less than 8Lbs.

The front seats only have 4 bolts each holding them in place + 1 wiring harness for the power seats and 1 for the airbags.

I did mine incrementally with the floor and trans tunnel being first.

I have longtube headers on the car along with an aftermarket K-Member and very firm urethane motor mounts and it reduced the sound, vibration and especially the amount of heat that was coming into the vehicle through the floor.

With the car having folding rear seats the next area which will be tackled will be the trunk area since I installed the new mufflers last fall.

**300B** · 03-12-2008, 05:24 PM

Messing around with sound insulation is like pissing in the wind vs a good set of quiet tires like Goodyear Comfortreds for example.I`ve got them on my Benz and they`re the quietest tires i`ve ever owned.

**thump_rrr** · 03-12-2008, 06:53 PM

Originally Posted by M54

Messing around with sound insulation is like pissing in the wind vs a good set of quiet tires like Goodyear Comfortreds for example.I`ve got them on my Benz and they`re the quietest tires i`ve ever owned.

Driving on a set of comfortreads is like driving on tires made of jello. I`ll stick to my Michelin Pilotsport PS2 thanks.

Road noise isn`t the only thing people are trying to abate by adding sound deadening material.

**300B** · 03-13-2008, 06:49 PM

Originally Posted by thump_rrr

Driving on a set of comfortreads is like driving on tires made of jello. I`ll stick to my Michelin Pilotsport PS2 thanks.

Road noise isn`t the only thing people are trying to abate by adding sound deadening material.

Well what else on the car touches the road?

**TortoiseAWD** · 03-14-2008, 09:47 AM

Originally Posted by M54

Well what else on the car touches the road?

Check again what thump_rrr said: "Road noise isn`t the only thing people are trying to abate by adding sound deadening material."

Tires are the only thing that touch the road, but NVH (noise, vibration, harshness) in the cabin comes from much more than just tires alone. For drivers that are performance-oriented, sacrificing handling for a quieter ride isn`t going to be acceptable. This thread is (mostly) about what can be done to quiet the cabin *other* than swapping out tires.

Tort