Sound deadening/proofing questions

[i-WERKS]

I've been looking into this and I'm not sure if it does what I'd like it to do. From reading most sound deadening posts, most people only say that it improves the sound of the bass which is not really my concern.

What I really want it for is to reduce the sound of wind/road noise. The main reason is that I find that my magnaflow exhaust is kinda loud from the inside.
Would sound deadening kits like brownbread and dynamat help quiet down outside noise?
Is there any cheaper alternatives to brownbread/dynamat which are just as effective?
Should I be expecting a hugh difference in noise reduction?
What are the pro's and con's of getting the EP sound proofed?

[Btrthnezr3]

I'm not sure how effective it would be for your exact application/needs but "Peel and Seal" is a cost effective alternative to dynamat. I found some at my local lumber supply shop (Mccoys) but I heard they have it at Home Depot and Ace Hardware sometimes. It is similar in look to dynamat but is a little bit thinner. It was like 25 dollars for a large roll about 1 foot high and about 7 inches in diameter. One con from this is that if you use a lot of this sort of material....weight gain for your EP will arise. I used this in mthe trunk of my Peel and Seal in my 4 door but for bass/trunk rattling control. Worked fairly well. :D

[raiyo]

Check out this page, it'll might help.

http://www.cardomain.com/memberpage/245900/2

[i-WERKS]

thanks raiyo.
I read it and most of it is on how to install.

My main reason for considering this is the exhaust noise.
Secondly is the road noise.

Would any of these products reduce the noise?

[Spazhead]

sound deadening material like dynamat is used to adsorb vibrations from interferring with the sound quality. It's not a sound proofing material. People say their Bass sounds better because they have used the dynamat to stop their trunk sheet metal from vibrating or their door panels from vibrating and even their licence plates.

If your exhaust is too noisy, then there is not much you can do but to change it. Car makers use that heavy carpeted stuff or foam to absorb road noise, if you lift up your carpet, you would probably see some sound deadening material. To add more sound deadening material to your car would just weigh it down more thus neutralizing any power gains your exhaust gave you.

[i-WERKS]

Originally posted by Spazhead
sound deadening material like dynamat is used to adsorb vibrations from interferring with the sound quality. It's not a sound proofing material. People say their Bass sounds better because they have used the dynamat to stop their trunk sheet metal from vibrating or their door panels from vibrating and even their licence plates.

If your exhaust is too noisy, then there is not much you can do but to change it. Car makers use that heavy carpeted stuff or foam to absorb road noise, if you lift up your carpet, you would probably see some sound deadening material. To add more sound deadening material to your car would just weigh it down more thus neutralizing any power gains your exhaust gave you.

So basically there's no need for sound deadening unless you have rattles.

I wonder if the magnaflow mid pipe would bolt onto the stock muffler. It'll probably be quieter and still have some gains.

[00-ITR-373]

On the back of the carpet is a funky material made up of strands of all kinds of fibers. My guess would be that if you went to a carpet store, they might have some more carpet backing. But that might not be too much for acoustics. Dynamatt IS more for a different application. For reducing the noise in the cabin you do not want that to touch the floor first, otherwise you might transmit more noise into the cabin. You need more of an insulator if you will. If you had something very thin, maybe 2-5 mm in thickness that you could put on the floor first, then a layer of thin dynamatt on top of that, you'd greatly reduce cabin noise. p.s. I have a pic going in the main discussion area of an NVH improvement the '04 Si has that no one has mentioned yet. You could swap the part onto your '03 for increased noise reduction as well. Hope this helps.

[BarracksSi]

[QUOTE]Originally posted by i-WERKS
So basically there's no need for sound deadening unless you have rattles.[quote]

Personally, I'm still not convinced that sound deadening will actually filter out road noise. It would make more sense if it were used to deaden the metallic resonances of the car's construction (in other words, to keep it from going "clang" when sound gets to it).

I wonder if the magnaflow mid pipe would bolt onto the stock muffler. It'll probably be quieter and still have some gains.

Worth investigating -- I'm sure you already know that people are discovering that the stock muffler is really good, power-wise.