Roxul or 703 question?

[Jim Holtz]

I've not used anything but foam to line the walls of cabinets. I've read that Roxul or Owens Corning 703 rigid fiberglass panels offer better and lower frequency absorption rates. Robert just posted a link to a vendor in a different thread that offers decent prices.

My question is, are these materials acoustically transparent or do they take box volume? Also, is one preferable to the other and how do you attach it to the cabinet walls?

Thanks!

Jim

[ThomasW]

OC 703 fiberglass is fiberglass, the compressed boards are a little easier to work with compared to the batts, but both work the same.

703 has a higher absorption coeff compared to Roxul so it's what I'd use

http://www.bobgolds.com/AbsorptionCoefficients.htm

I'd use hot glue for 703

[---k---]

You use it inside your speaker cabinets? Really? I didn't think it was good for that.

The other big difference I believe between 703 and Roxul is that the 703 is pretty rigid and will stay in place. The Roxul, I've been told, is kind of floppy and needs a support frame.

[ThomasW]

If you search back through some of Pete Mazz's projects you can see he use 703 inside his boxes

[Jim Holtz]

OC 703 fiberglass is fiberglass, the compressed boards are a little easier to work with compared to the batts, but both work the same.

703 has a higher absorption coeff compared to Roxul so it's what I'd use

http://www.bobgolds.com/AbsorptionCoefficients.htm

I'd use hot glue for 703

Hi Thomas,

Thanks for the prompt answer. I'll have to give it a try in my future projects. There's always another one isn't there.

Jim

[cjd]

You use it inside your speaker cabinets? Really? I didn't think it was good for that.

Yes... and you may want to use it in your upcoming project, actually.

I want to snag a bunch for the HT and more to set up temporarily when measuring speakers. So if we have to order in bulk(ish) and you want some but not all, holler.

C

[---k---]

Thomas, don't know what I was thinking. I'll search for one of Pete's projects. I'm kind of interested now.

Chris, I have a few 1" thick sheets of 703 and a bunch of scrap left over. But, let me know when you order it. Having a few extra around will probably come in handy for something.

[ahaik]

Hi,

Home Depot has accoustic insulation, I used that with spray adhesive
in the Statements, its 3.5" thick, the stuff that goes between the studs without the paper backing.
I must say the base is extremely powerful and very tight and accurate, as tight as I ever heard from any speaker.
Its a little fluffy though so I stapled it around the woofers

Jim,
I apologize for not posting my impressions yet ops: , this project had a some toll on my wife so I am lowering profile for a few days, I also need to do some more intensive listening.

Asi.

[Jim Holtz]

Hi,

Home Depot has accoustic insulation, I used that with spray adhesive
in the Statements, its 3.5" thick, the stuff that goes between the studs without the paper backing.
I must say the base is extremely powerful and very tight and accurate, as tight as I ever heard from any speaker.
Its a little fluffy though so I stapled it around the woofers

Jim,
I apologize for not posting my impressions yet ops: , this project had a some toll on my wife so I am lowering profile for a few days, I also need to do some more intensive listening.

Asi.

Hi Asi,

No worries! You really dove into building the Statements and I can understand the toll it takes on the rest of the family. Been there, done that!

Relax, enjoy the Statements when you can, and let the family get to know you again. :T

Jim

[joecarrow]

Hi,

Home Depot has accoustic insulation, I used that with spray adhesive
in the Statements, its 3.5" thick, the stuff that goes between the studs without the paper backing.
I must say the base is extremely powerful and very tight and accurate, as tight as I ever heard from any speaker.
Its a little fluffy though so I stapled it around the woofers

Jim,
I apologize for not posting my impressions yet ops: , this project had a some toll on my wife so I am lowering profile for a few days, I also need to do some more intensive listening.

Asi.

Listening to the speakers, or your wife? :P

Sorry, I couldn't resist!

[PMazz]

I highly recommend the 2" 703 as speaker lining material. I used hot glue to attach but it takes quite a bit for a large enclosure. Get yourself one of those break-away retractable razor blade knives to cut it also helps.

[---k---]

Pete, wow, 2" almost all the way around. Which project is that? I did a search yesterday and started skimming your brothers MTM thread - didn't have time to read the others. I see that definitely isn't an MTM.

Did you do any comparison testing (listening or otherwise)? Does anyone have any links to testing? I'm just curious. I fully understand how it absorbs the low frequencies better. I'm trying to comprehend how it affects a sealed enclosure size. My gut tells me it would be different that say R30, but my gut is often wrong. I guess it doesn't matter the material density it just matters total weight of the fill versus the volume of the enclosure???

BTW, I use an electric carving knife to cut it. Works fantastic, like butter.

[PMazz]

The tall ones are my line arrays. Check out the Birth of a Media Center in my sig.

I never did testing with and w/o but every enclosure I've lined with it sounded great, whereas with polyfill the results were mixed.

I like the carving knife idea. I've used them to cut foam but never thought to use it for the 703.

Pete

[---k---]

The only problem with the carving knife is that I had to buy a second one. For some reason my wife wouldn't let the one I used to cut the 703 back into the house.

[whoaru99]

The only problem with the carving knife is that I had to buy a second one. For some reason my wife wouldn't let the one I used to cut the 703 back into the house.

You told her? :E

[Jim Holtz]

How about Roxul Rockboard?

Thomas had indicated that Roxul was harder to work with since it wasn't stiff. How about Roxul Rockboard? The price is better than 703 and it appears to be more rigid? Is it acoustically transparent too?

Here's a link

Thanks!

Jim

[robertwb70]

It's my understanding that the rockboard is equivalent to Owens Corning 705
-6 lbs per cubic foot density, supposed to be better suited for bass panels for room acoustics.

There are some measured results for room treatment on Ethan Winers site (realtraps).

Not sure how any of that info might apply to use inside speaker enclosures though...

Robert