Lowes now carries 7 1/4" thick fiberboard should i get some?

[John California]

Shop Roxul 6-Pack 47"L x 15-1/4"W x 7-1/4"D 30-R Stone Wool Insulation Batts at Lowes.com
Im guessing itll absorb bass really well compared with other products, only ~$40 for for 30 sq feet. They also carry other roxul of varrying thickness if you search roxul. Im about to order it, any reason i shouldnt?
I looked this up to check if anyone else had posted it, i did find some one mention that 3" roxul had .52 absorption at 100hz, would 7", over twice as thick give me 1.04 at 100hz or anywhere around that? Ill see about having it 5" or so away from the wall to help with low end absorption.

 

[Massive Master]

I'd buy 'em... But I'd get the 23.5" wide version (4-pack, around the same price).

 

[John California]

ya

I'd do it, but i end up barely loosing any square footage and have more choice with placement. Also i dont see any reason why other than i would need fewer frames but im not worried about that. Any other reasons?

 

[Massive Master]

Mass x Area --

 

[John California]

So how well do you guys think this will absorb? If i keep it 6" off the wall would it get to 60hz at least a little? Hoping it will clear up my bass, both recording, mixing, and for my speaker set-up.

 

[Capt Hair]

Good find! Lets just hope they don't get smart and start labeling them as "acoustic" fiberglass and charge an extra $40.

Only way for sure to know if you would get full absorption down to 60hz is to test your room once you have the bass traps in place, we could guess all day, but you just don't know until you take actual measurements. And as Master said, get the 23.5 width, you'll get more coverage of the corner that way.

 

[chronicle]

i did find some one mention that 3" roxul had .52 absorption at 100hz, would 7", over twice as thick give me 1.04 at 100hz or anywhere around that?

I looked for absorption coefficients of this product, even in the Technical Library but couldn't find anything. Where did you see this? As to you question, no one can answer that except a lab that has tested it. Testing in your room will not tell you the absorption coefficient either. Acoustical Labs have rooms certified for a consistent RT-60 and use uniform testing Standards. Even then, very seldom will they certify a product absorption coefficient below 100hz. Of course, my disclaimer is in full force here.

 

[Capt Hair]

probably from this: http://www.bobgolds.com/AbsorptionCoefficients.htm

 

[WhinyLittleRunt]

I'm going to be using these as room/ceiling insulation in my basement studio that's in the middle of construction at the moment. My father was at Lowe's recently and mentioned what I was doing to an associate and he recommended it saying he used it to build a music room for his son and it really helps isolate; much better than standard fiberglass insulation.

 

[chronicle]

Well I looked at Bobs chart and still didn't see the product in question. The only Roxul listed was RIGID ROCKWOOL...not flexible batts... Comfortbatts are flexible batt insulation. Perhaps I'm not seeing what you found though.

 

[Capt Hair]

Comfortbatts would be better for absorption. From everything I've studied, regardless of the material, as long as it has absorption properties (a porous material), all that matters is the density of the product and how much area it covers. Rigid fiberglass is better for isolation, while looser batts are better for absorption/room treatment. Rigid fiberglass, however little, is slightly reflective and is great if your isolating a room when you need to both reflect and absorb the low end energy that your trying to keep in/out, but not for treating a room.

Point being, by using some common sense, you don't need the exact absorption coefficient to know if it's effective and can reach to a certain range. You don't need a graph to tell you if something works, use a little basic math and your head. Density and surface area...if an almost identical material is absorbing at a certain range at 3/4 the thickness and density, you best believe that something with that much more mass is able to do the same.

Also this:

"The absorption coefficients that are typically published for acoustical materials are found using the reverberation chamber method. This method yields random incidence absorption coefficients, which are not percentages. Normal incidence absorption coefficients are percentages. The two are often confused in the literature. A material that has a random incidence absorption coefficient of 1.22 is simply a better absorber relative to a material with a random incidence absorption coefficient of 0.67 for the same frequency band, all other factors being equal. The numbers should not, however, be treated as an indicator of the percentage of sound absorbed by the material." by Savant aka Jeff D. Szymanski

 

[RAMI]

Rigid fiberglass is better for isolation, while looser batts are better for absorption/room treatment. Rigid fiberglass, however little, is slightly reflective and is great if your isolating a room when you need to both reflect and absorb the low end energy that your trying to keep in/out, but not for treating a room.

You need to back that up with some references or explanations.

Rigid fibreglass is not good for absorption? That's the complete opposite of everything I've ever learned from people I trust.

"reflect low end energy"????? Why would anyone want to "reflect" anything? Isn't that the opposite of what you want treatment for (unless you meant "diffuse", in which case that's wrong because absorbers don't diffuse).

I'm not with most of what you said, but hopefully you can explain it.

Thanx.

 

[chronicle]

Rigid fiberglass is better for isolation, while looser batts are better for absorption/room treatment.

Hogwash. Rigid fiberglass won't isolate a damn thing, except fire. And batt insulation, while having absorption qualities, will not perform as well as rigid fiberlass...PERIOD. If it did, then various acousticians specifying rigid fiberglass for World Class studios around the world as the main absorption product are either stupid, ignorant, con artists, or stock holders in the companys that produce it. However...I think not.

I don't know what you were smoking when you came to these conclusions...but you would behoove yourself to do some research.

 

[RAMI]

Hogwash. Rigid fiberglass won't isolate a damn thing, except fire. And batt insulation, while having absorption qualities, will not perform as well as rigid fiberlass...PERIOD. If it did, then various acousticians specifying rigid fiberglass for World Class studios around the world as the main absorption product are either stupid, ignorant, con artists, or stock holders in the companys that produce it. However...I think not.

I don't know what you were smoking when you came to these conclusions...but you would behoove yourself to do some research.

Thank God......I thought it was just me that couldn't find one thing in that post that made sense to me..

 

[chronicle]

ooh ooh........old fart syndrome strikes again...

Thank God......I thought it was me.

There are some caveats due here.


Well, with all due respect an apology to Capt Hair, it appears I needed to update my own knowledge in regards to the R-30/rigid fiberglass comparison. At least when it comes down to absorption performance..however, there are other caveats...ie../PRICE/AVAILABILITY/SPACE CONSTRAINTS/EASE OF USE,HANDLING/INSTALLATION

I still stand by my statement regarding isolation, but for all intents and purposes, it appears that R-30 is indeed applicable to use as a viable alternative to rigid fiberglass. However, there ARE some caveats.

I suggest reading this thread Rami.

Pink fluffv vs. Rigid cost vs. Performance question.... - Gearslutz.com

Although, 4" rigid fiberglass with an airgap is still recommended as EXCELLENT

But is think I still owe an apology to Capt. Hair....


Ok guys, it appears this forum is indeed due for some new insights/information/tests/ and opinion upgrades. Especially mine. What can I say. Other than my original opinion was based on reading older information that was TRUE at the time. Newer products, insights and experience now corrects my opinion. Capt Hair, although some of your statements still seem incorrect, your opinion regarding the absorption qualities of R-30 batt insulation appear correct...with the caveats applied. However, I still think that given SOME of those caveats, rigid fiberglass is a better choice. It depends on how those caveats influence ones choice on a project by project basis. So, I stand corrected. Won't be the last time either.

One other thing though.. I'm going to personally ask the Studio designers I know, who have chosen rigid fiberglass for very expensive projects, why they used it in the places they did, as it appears R-30 COULD have been used in some. But I'm sure they have their reasons.

Ok, nuff outta me for now.

 

[RAMI]

There are some caveats due here.


Well, with all due respect an apology to Capt Hair, it appears I needed to update my own knowledge in regards to the R-30/rigid fiberglass comparison. At least when it comes down to absorption performance..however, there are other caveats...ie../PRICE/AVAILABILITY/SPACE CONSTRAINTS/EASE OF USE,HANDLING/INSTALLATION

I still stand by my statement regarding isolation, but for all intents and purposes, it appears that R-30 is indeed applicable to use as a viable alternative to rigid fiberglass. However, there ARE some caveats.

I suggest reading this thread Rami.

Pink fluffv vs. Rigid cost vs. Performance question.... - Gearslutz.com

Although, 4" rigid fiberglass with an airgap is still recommended as EXCELLENT

But is think I still owe an apology to Capt. Hair....


Ok guys, it appears this forum is indeed due for some new insights/information/tests/ and opinion upgrades. Especially mine. What can I say. Other than my original opinion was based on reading older information that was TRUE at the time. Newer products, insights and experience now corrects my opinion. Capt Hair, although some of your statements still seem incorrect, your opinion regarding the absorption qualities of R-30 batt insulation appear correct...with the caveats applied. However, I still think that given SOME of those caveats, rigid fiberglass is a better choice. It depends on how those caveats influence ones choice on a project by project basis. So, I stand corrected. Won't be the last time either.

One other thing though.. I'm going to personally ask the Studio designers I know, who have chosen rigid fiberglass for very expensive projects, why they used it in the places they did, as it appears R-30 COULD have been used in some. But I'm sure they have their reasons.

Ok, nuff outta me for now.

I wasn't questioning WHICH of the 2 is better for absorption, because I'm not qualified to make that determination.

There are a few other statements regarding "reflecting", the claim that rigid fibreglass is not good for absorption, etc.....Some of those statements didn't make sense to me. It was no attack on Capt. Hair., which is why I asked him to explain.

 

[John California]

I wasn't questioning WHICH of the 2 is better for absorption, because I'm not qualified to make that determination.

There are a few other statements regarding "reflecting", the claim that rigid fibreglass is not good for absorption, etc.....Some of those statements didn't make sense to me. It was no attack on Capt. Hair., which is why I asked him to explain.

I interpreted that as him saying that rigid fiberglass, being rigid(hard) would reflect more than comfortbatts which are much softer, so they'd let less sound through(to the other side) as what isn't absorbed would be reflected. He wasn't saying that either wouldn't work for either job but that one would be more suitable to that job while also considering monetary and spacial issues.
Again this is just my interpretation of his comment.

 

[RAMI]

I interpreted that as him saying that rigid fiberglass, being rigid(hard) would reflect more than comfortbatts which are much softer, so they'd let less sound through(to the other side) as what isn't absorbed would be reflected. He wasn't saying that either wouldn't work for either job but that one would be more suitable to that job while also considering monetary and spacial issues.
Again this is just my interpretation of his comment.

Yeah, you could be right. I think it's a matter of terminology. The Captain might be 100% right about everything he said, but I might be mis-understanding some of his wording.

I think I might be getting thrown off because I always thought, maybe erroneously, that rigidity was a result of density. When you pack something dense enough, it becomes rigid is what I thought. Because of that, I thought that if something is loose (or whatever the opposite of "rigid" is), then it can't be dense.

I didn't think that rigidity would increase reflections, but I could very well be wrong.

 

[Massive Master]

Rigid fiber is better at absorbing low end and just fine for absorbing a decent amount of top end without robbing the space completely of ambience. And as about 90% of your problematic energy is almost universally in the low end, that's usually the way to go.

Even "fluffy stuff" - To make it reasonably effective, you need to leave it packaged (where it's under a certain amount of pressure).

I don't know of a situation where soft stuff would be preferred. And it certainly doesn't reflect like a bare wall would...

 

[Manslick]

Something in the specs looks odd to me.