Sound proofing to reduce road noise

[cmartins1963]

I found interesting.

Super Soundproofing Hoodliner

[300B]

I`m looking to see if Autopians can clarify the issue of how to efficiently reduce noise in cars. This is one of the best sites on the web for intelligent inquiry about cars, and this is a topic with a lot of half-baked posts on other sites.



I`ve been doing a lot of research on noise reduction in cars. On many sites, the Dynamat or other heavy matting is put on every square inch of interior door skins and floor panels. Maybe a thin bit of closed cell foam is then put on top of this.



But when I look at scientific research on auto noise reduction, it looks like recent computer models are showing how to REDUCE the amount of metal damping to optimize weight/noise. In Europe, they discovered that they could get better sound damping and save both bulk and weight by using thin layers of dense and less dense felt to absorb sound. Here`s a press release about an interesting recent study by the EU: Smart sound insulation in cars leads to lower environmental emissions



I just used old yoga matting in the A-pillars of my civic to reduce squeaks and deaden the sound.



Anybody here have ideas about efficient and effective noise reduction in cars?

Start with the main source,tires!



The right tires will have more impact than a 100lb`s of dynamat would.

[Glossy McGlosserton]

Yeah, I thought the super soundproofing web site was interesting, too. But it looks sort of jack leg, and I wouldn`t feel comfortable spending $80-some without knowing someone who used the product and said it was worth it.



Anyone here used this hoodliner, or any other?

[nonsensez9]

I really underestimated how much material was required.

I`m looking at doing the same this year. Roughly how many sqare feet did it take to do the floor? did you do the doors and roof too?

[thump_rrr]

I`m looking at doing the same this year. Roughly how many sqare feet did it take to do the floor? did you do the doors and roof too?

Almost 40 sq ft for the floor alone.

I haven`t done the doors or roof yet.

[boon4376]

I have a question, A lot of noise i get is mostly wind noise as my saab is pretty well insulated from road noise.



I`m guessing most of this is from 14 year old seals around the doors and such, and would putting caulking stuff behind the strips (making them a little thicker) create a better seal with the door against the frame and quiet wind noise down a lot? Or does that sound silly?

[cmartins1963]

I would buy new seals.

[xtremekustomz]

Acoustic deadening such as fleece and other materials has been done alot with home audio, in sound rooms, and in movie theatres for a LONG time. The problem is that you have to have a certain thickness to absorb certain frequencies. When you add a deadener to to metal it adds mass to it. If I`m not mistaken some high end car manufacturers even use sand to fill in the floorboards to reduce outside noise. Butyl based and asphault based deadenerss are used alot in car audio and it isn`t uncommon for some vehicles to have 8+ layers of this stuff inside. I have 4 layers in certain places in my truck along with a material called ensolite which is a foam that works as a sound barrier as well. I even know of guys that have lead sheets sewn into their floor matts to reduce vibration. It really does make a huge difference inside the cabin. As mentioned though....tires to make a big difference as well. Don`t expect a truck that has 35" super swampers on it to greatly benefit from this.



Here is some neat info if you wanna do some reading:



Sound Deadener Showdown





My Truck:

[Glossy McGlosserton]

So, extremecustomze, did you do any spl measurements on that truck before and after? And did you notice any gasoline mileage reduction after all that deadener was added? Looks like it would add 50-75 pounds of weight.

[Glossy McGlosserton]

Boon 4376, if you are talking about the foam rods that are used to cram into spaces prior to caulking big gaps (sometimes called `backer rods`), I think that might be a pretty good idea to get a better seal.



There was a fellow who experimented with small diameter rods like that to get a better seal on his windows. He also found that most of the noise was from the small corner where the window met the door frame, and that a very small bit of the foam stuffed in that corner solved it. But many folks felt that the foam backer rod really helped seal out noise.



$5 foam tube + rubber door seals = less wind noise? - Club Lexus Forums This is the thread. "$5 foam tube + rubber door seals." Go to the third page or so, and there is an improved method suggested by another poster. Also, if you just read the beginning, you will buy 3/8 inch foam, which is probably too large, as folks were cutting it in half length-wise to get the seals to fit back on properly.



Frankly, the seals on my 2003 Civic are like new, but I still think that they should be tighter to limit wind noise better. So I think even with like-new seals, this method could be helpful.

[300B]

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

Pissing in the wind my friend.



Tires are the easiest and best way to achieve this.

[300B]

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 your comparing apples an oranges as not everyone out lives a 1/4" mile at a time.



BTW,have you ever owned a set of Comfortreds?

[tomstin]

Hey Sheri, how`s the red truck? It`s been awhile since the detail meet at Brandon`s. The installation in my Tacoma was similar to xtremekustomz. I installed RaaMmat and Ensolite RAAMaudio - Quality and Value in Automotive Sound Deadening I have a PDF write up with some pictures if your intersted, send me a PM.



Now, I have no scientific data to support my conculsion, but the truck is MUCH eaiser to cool in the summer and is signifcantly quieter going down the road. Installation is a time consuming task. And, bring an extra dose of patience!



My only regret, I didn`t do it sooner!



If you contact Rick at RAAMaudio, you will find him very helpful.

[xtremekustomz]

No I didn`t do any measurements before or after. I actually took the factory wheels and tires off after I painted it and put on the 22`s with low profile tires and it got even quieter. I`d say it added about 50-60 lbs cause I used 2 rolls of Raamat. As for gas mileage, I get better mileage it didn`t change any right after I did it. I actually get better gas mileage now that I have the 22`s on there. Like the guy above said....give Rick at Raamat a call and he will be MORE than helpful. He`s really a great guy and he will always have my business. I think I`ve ordered 5 or 6 rolls from him in the last year. For the rest of the build up of my truck you can go to: http://www.cardomain.com/ride/2677023 Although by mid summer the paint scheme will be changing drastically

[TortoiseAWD]

M54,



Either post on-topic, or don`t post at all. This thread is NOT about tires.



Do it again, you`ll be in timeout for a week.



Tort

(moderator)