Sound Deadening

[kevman5002 10+ year member]

First let me say you guys have a great forum.

I've been researching sound deadening and came across LyTherm Max Link. I've searched here and google and I can't find a lot of info about it. It looks like it'd be pretty good for use over a layer of Damplifier or BXT or whatever.

Anyone have any experience with this? It's a little pricey, would Second Skin Luxury Liner be a better choice? Or something else all together? Cool and Quiet seems to have a bunch of good looking products. Just curious about what other options are out there.

And since I see it linked a lot, I have read the Sound Deadener Showdown article.

Click to read more...

 

[audioholic 5,000+ posts]

Never heard of it, or the company for that matter (doesn't mean anything tho). The product looks to just be very similar to carpet backing, but with more heat resistance. Id think a product with multiple layers of different density materials (like luxury liner iirc) would work better. But I have no experience with this product to say for sure, obviously.

 

[kevman5002 10+ year member]

Bumping with an additional question.

I'm in a position to acquire vast amounts of open cell polyurethane foam. It's in stripes 1/2 inch thick * 5 inch wide by 12 inches long. Unfortunately I have no pics or other information which may make answering this question hard, but would this work as a decent deadener? Obviously it won't be perfect, and will be a pain to work with, but like I said it's free. I would probably apply this over Damplifier. Any incite would be appreciated.

 

[audioholic 5,000+ posts]

Open cell foam makes for a poor sound absorber. You want closed cell foam.

 

[kevman5002 10+ year member]

I'm not trying to say it's on the same level, but Second Skin's Luxury Liner is open cell.

 

[audioholic 5,000+ posts]

Well ya got me there. I know closed cell offers more of a barrier than open cell, just by the actual nature of each cell having a complete wall (more material for the sound waves to pass thru). Maybe Ant will come in and let us know why luxury liner uses open cell. Its probably frequency related.

 

[FoxPro5 5,000+ posts]

Open cell foam makes for a poor sound absorber. You want closed cell foam.

You have that backwards, actually.

Open cell foam works by forcing sound through the cells. It's structure converts sound to heat.

Closed cell has nothing to offer via absorption because the cells are closed. It can diffuse sound, but not absorb it. Diffusion is not absorption.

 

[FoxPro5 5,000+ posts]

First let me say you guys have a great forum.
I've been researching sound deadening and came across LyTherm Max Link. I've searched here and google and I can't find a lot of info about it. It looks like it'd be pretty good for use over a layer of Damplifier or BXT or whatever.

Anyone have any experience with this? It's a little pricey, would Second Skin Luxury Liner be a better choice? Or something else all together? Cool and Quiet seems to have a bunch of good looking products. Just curious about what other options are out there.

And since I see it linked a lot, I have read the Sound Deadener Showdown article.

Looks like if you used the product as it's meant to be used...to absorb heat...then it would be a good choice. If your goal is to block sound, it's the wrong product.

Luxery Liner is a decoupled barrier with a 1 lb/sqft mass layer. It offers some absorption with it's open cell foam, but not much. It's a better blocker than an absorber.

 

[audioholic 5,000+ posts]

Looks like if you used the product as it's meant to be used...to absorb heat...then it would be a good choice. If your goal is to block sound, it's the wrong product.
Luxery Liner is a decoupled barrier with a 1 lb/sqft mass layer. It offers some absorption with it's open cell foam, but not much. It's a better blocker than an absorber.

Im not trying to sound contradictory, but didn't you just tell me the open cell is a better absorber?
Ive been under the impression open cell foam is a poor choice for sound deadening in general. Obviously that's wrong if SS offers an open cell product. If closed cell is for blocking, and open cell is for absorbing, which method should be employed for what situations? Road noise versus retaining interior sound?

Thanks for the clarification.

 

[FoxPro5 5,000+ posts]

Im not trying to sound contradictory, but didn't you just tell me the open cell is a better absorber?
Ive been under the impression open cell foam is a poor choice for sound deadening in general. Obviously that's wrong if SS offers an open cell product. If closed cell is for blocking, and open cell is for absorbing, which method should be employed for what situations? Road noise versus retaining interior sound?

Thanks for the clarification.

Yes I did. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Define "deadening."

The purpose of any foam in a composite barrier like LL is to float the barrier away from the surface, not really to absorb noise.

Open cell foam is a broad band absorber that works better AWAY from the noise source. In home studios and such, OCF is shown to be more absorptive toward the center of the room. If you take something like LL with OCF and place it RIGHT NEXT to the noise source, how well will it function as an absorber?? Thus my comment of it not working very well. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Closed cell foam offers some block-ablility (defraction), but not much. Mass Law governs block-ability. "How massive is the CCF", should be the primary question. If the answer is "not massive at all" then you have a poor barrier and a poor absorber. Best bet is diffusion. Difussion is not refraction nor is it absorption.

As a general rule:

CCF for thermal apps. Great heat container/blocker

OCF for absorbtion. Use away from the noise source where the particle velocity is highest.

Barrier composites as close to the noise source as possible.

 

[kevman5002 10+ year member]

How do people feel about Hushmat? Aside from it being insanely expensive.

 

[blazeplacid 10+ year member]

just od the second skin, its worth the money

the stuff is still exactly where I put it.

I has survived a 110+ texas summer

 

[mdillon 10+ year member]

how can you find out what is open or closed cell? im assuming it will be stated somewhere on the retail packaging?

 

[bigbangtheory 5,000+ posts]

How do people feel about Hushmat? Aside from it being insanely expensive.

Had it in my Cutlass Supreme and it worked. I like the fact you can also choose black or silver. I would always go with black if I had the choice, but the stuff I use now, is silver and I have two different brands in my car. I think more companies should use that aspect.

With that said, I got mine at dealer cost back then because I was good friends with the guy that got it for his shop. So he hooked me up. There are better alternatives than Hushmat due to their expensive price.

I say look up Second skin as it is decently priced and works just as well if not better. I also have a budget deadener in FatMat and everyone talks ish about it not working. I have to disagree with that. Works fine in my car and I have used quite a bit of deadener in my day from Hushmat, Dynamat, Second skin and other really cheap deadeners.

I also hear Raammat BXT is really good to use too, but have no expierence with that myself.

 

[kevman5002 10+ year member]

I'm probably gonna go with second skin, however the more I research the more products I find. So here's another that I've got to ask about. Sound Proofing

They actually list an STC rating which is nice. But then again they could just be making it up. Let me know what you all think. Take notice of the LB/sq. Ft.

The same company also sells a foam.

Also just found R-Blox A little pricey, but again just wondering how people feel about it. Also I can't find if it's Asphalt or Butyl based, I assume Butyl.