Car sound proofing.

[eldorado99]

I have all my seats and carpet out right now and I'm looking to replace the sound proofing in my car. In the 70's they seemed to use burlap and paper which disintegrates as soon as I pick it up (70 Cadillac). I would like to make this car as quiet as possible and I don't care about weight or thickess of the material much.

I was thinking carpet underlay as a substitute, it's cheap, easy to get, and hopefully effective. I don't want to go buy a bunch of dynamat because of the price, and I don't know much about the spray on stuff. Anyway what do you guys suggest for the best sound proofing materials?

 

[tasmanian]

Porous absorbers: Common porous absorbers include carpet, draperies, spray-applied cellulose, aerated plaster, fibrous mineral wool and glass fiber, open-cell foam, and felted or cast porous ceiling tile. Generally, all of these materials allow air to flow into a cellular structure where sound energy is converted to heat. Porous absorbers are the most commonly used sound absorbing materials. Thickness plays an important role in sound absorption by porous materials. Fabric applied directly to a hard, massive substrate such as plaster or gypsum board does not make an efficient sound absorber due to the very thin layer of fiber. Thicker materials generally provide more bass sound absorption or damping.

Might help.

 

[Heisenberg]

Edit: n/m - can't read.

 

[nutxo]

at one time I was thinking of trying roofing felt and spray adhesive.

I'd bet money it would work.

 

[Howard]

Constrained layer damping on the metal will be superior to free-layer (one side only) damping. Adding additional mass will also help, though it may reduce the effectiveness of the CLD.

http://www.earsc.com/pdfs/engineering/CLD.pdf

 

[I Saw OJ]

I know you dont wanna do Dynamat, but its really your best choice. I had it in my Camaro and not only did it help reduce noise, but vibrations as well. It might also have been my imagination, but it seemed to keep the cabin quite a bit cooler.

 

[Squisher]

A cheap alternative to Dynamat is a material used in roofing called "Ice and water shield"

The problem is the smell varies a lot from one manufacturer to another. You'll need to do some sniffing around at your local roofing supply place. Home Depot has it.

 

[rhino56]

Originally posted by: Squisher
A cheap alternative to Dynamat is a material used in roofing called "Ice and water shield"

The problem is the smell varies a lot from one manufacturer to another. You'll need to do some sniffing around at your local roofing supply place. Home Depot has it.

the smell goes away eventually.

 

[jsbush]

Dynamat isn't really a sound proofing material. It's used in cars to stop vibrations and unwanted noise.

From my understanding, dynamat just helps you hear the music as it was intended.

 

[TechBoyJK]

if you dont want to pay for dynamat, there are cheaper, competitive solutions out. check out caraudio.com forums. there is a "speakers" section with a stickied thread on car sound proofing

 

[JM Aggie08]

HushMat

 

[jdoggg12]

http://www.raamaudio.com/cgi-bin/index.cgi?p=pr Far superior to dynammat and far cheaper - i have over 100sq foot of this in my integra and you can barely hear my 2 12's powered by 1200 watts from outside of my car when the windows are up.

 

[Aharami]

Originally posted by: jdoggg12
http://www.raamaudio.com/cgi-bin/index.cgi?p=pr Far superior to dynammat and far cheaper - i have over 100sq foot of this in my integra and you can barely hear my 2 12's powered by 1200 watts from outside of my car when the windows are up.

yep. raammat is awesome. but its not a sound insulator. none of the variations are. You'd need ensolite if you want to do sound proofing

 

[sjwaste]

How much of this stuff did you need to do your doors, jdoggg? I'm past my days where I'm going to strip the interior of my Supra (did it once 8 years ago for the initial install of the amp), but my door skins and panels do rattle, so this might be a good product for me.

 

[buck]

Originally posted by: rhino56

Originally posted by: Squisher
A cheap alternative to Dynamat is a material used in roofing called "Ice and water shield"

The problem is the smell varies a lot from one manufacturer to another. You'll need to do some sniffing around at your local roofing supply place. Home Depot has it.

the smell goes away eventually.

Yup, and works pretty damn well. I did my previous car, alot of work and after a month, the smell was gone completely.

 

[jdoggg12]

Originally posted by: sjwaste
How much of this stuff did you need to do your doors, jdoggg? I'm past my days where I'm going to strip the interior of my Supra (did it once 8 years ago for the initial install of the amp), but my door skins and panels do rattle, so this might be a good product for me.

I did a bit of overkill and went 2+ layers throughout the car. My doors now close witha deep "thump" like a luxury car might instead of the cheap tin can sound most hondas sound like. I can't stand hearing rattling parts as cars drive by with the bass blasting so i found every loose panel (including my license plate) and put the mat on it.

It made a very noticeable difference to road noise and a big difference to midbass response as well. The best part is that all the paneling is so thick now that nothing rattles when the bass hits. I go for SQL, not SPL so quality is very important. I built a fibreglass enclosure in the spare tire-well thats 2.5 cubic ft sealed. I can hit ~ 145dbs @ 45hz as it is, it was 140ish before the sound deadening.

 

[Cattlegod]

There is 3 things you can do. Put dynamat on all of the surfaces of sheetmetal to dampen and reduce the resonant frequencies in them. The next step is to put some type of carpet with a solid rubber backing EVERYWHERE you can fit it.

The final think and one that will help a lot for frequencies above 2000 is borrow an ultrasonic detector and find out where all of the holes are in your car. Get a caulk gun and seal up the holes.

After that, your car should ride as quiet as a '00 Cadillac.

edit: do them in order of
1 - seal up holes with caulk
2 - put on dynamat or something similar
4 - stuff everything with a carpet/rubber material.

 

[sjwaste]

Originally posted by: jdoggg12

Originally posted by: sjwaste
How much of this stuff did you need to do your doors, jdoggg? I'm past my days where I'm going to strip the interior of my Supra (did it once 8 years ago for the initial install of the amp), but my door skins and panels do rattle, so this might be a good product for me.

I did a bit of overkill and went 2+ layers throughout the car. My doors now close witha deep "thump" like a luxury car might instead of the cheap tin can sound most hondas sound like. I can't stand hearing rattling parts as cars drive by with the bass blasting so i found every loose panel (including my license plate) and put the mat on it.

It made a very noticeable difference to road noise and a big difference to midbass response as well. The best part is that all the paneling is so thick now that nothing rattles when the bass hits. I go for SQL, not SPL so quality is very important. I built a fibreglass enclosure in the spare tire-well thats 2.5 cubic ft sealed. I can hit ~ 145dbs @ 45hz as it is, it was 140ish before the sound deadening.

Is it doable with one roll if I don't go crazy?

The supra doesn't rattle much, but the doors arent properly enclosed. Add to that about ~100W RMS going through the 6.5" components mounted there, and it does vibrate.

 

[jdoggg12]

If you get 1 roll, that'll a good (on the hefty side) amount for 2 doors alone. You can always use what you need and sell the rest.

I have a set of Focal 6.5 components up front and there was a pretty noticeable gain in midbass after i matted my doors and matted the speaker mount.

If the rattling is whats bugging you, you can try the mat, if that doesn't help you can try foam. Be careful though b/c you DO NOT want to put it in the wy of your window rolling up and down ( i made that mistake haha)

 

[Raduque]

I hate to threadjack, but, what's the best way to use Dynamat to isolate speakers? Use it under the lip of the speaker between it and the mount space, or form it around the back of the speaker?

Trying to figure out how much I need to stop my rear doors in my truck from buzzing at good volumes.

 

[jdoggg12]

Originally posted by: Raduque
I hate to threadjack, but, what's the best way to use Dynamat to isolate speakers? Use it under the lip of the speaker between it and the mount space, or form it around the back of the speaker?

Trying to figure out how much I need to stop my rear doors in my truck from buzzing at good volumes.

http://www.pbase.com/matts009/dyn_extreme_speaker

Good speaker install job there...


But really - if you go with Mat, theres no need to waste your $$ on a brand name. I've been into relatively high end car audio for a long time.

read some of the user comparisons:

http://www.google.com/search?svnum=10&u...h+Images&ie=UTF-8&oe=UTF-8&sa=N&tab=iw

 

[Kaido]

QuietCar automotive coating

http://www.quietcar.net/

Comparison to Dynamat

 

[sjwaste]

Raammat seems to be the product in the sweet spot of price/performance. I'll probably get a roll of that and get to work on my doors. Whatever's left over can go towards the hatch area.

 

[Raduque]

Originally posted by: jdoggg12

Originally posted by: Raduque
I hate to threadjack, but, what's the best way to use Dynamat to isolate speakers? Use it under the lip of the speaker between it and the mount space, or form it around the back of the speaker?

Trying to figure out how much I need to stop my rear doors in my truck from buzzing at good volumes.

http://www.pbase.com/matts009/dyn_extreme_speaker

Good speaker install job there...


But really - if you go with Mat, theres no need to waste your $$ on a brand name. I've been into relatively high end car audio for a long time.

read some of the user comparisons:

http://www.google.com/search?svnum=10&u...h+Images&ie=UTF-8&oe=UTF-8&sa=N&tab=iw

I see...... you only use it to go around the lip of the speaker to isolate it from touching the door.

 

[jdoggg12]

Yea, the whole point of mat it to add mass to panels to reduce vibrations and to act as a buffer/washer between surfaces that rub together. Foams can be superior, but they are often VERY difficult to remove if there are mechanical issues in a particular area that you need to get to.

Think about a speaker not attached to anything - it will sound really bad, getting worse the lower the frequency.

Think about a speaker in a thin metal sheet - this will help, but not be much better since the sheet will vibrate with the speaker, reducing the speakers ability to move air.

Now picture that sheet with a dense layer of putty (dynamat) on it. The increased mass will reduce the movement of the sheetmetal and allow the speaker to work more effociently, while also reducing the sheet metals ability to creat noise of its own.