John Sayers' Recording Studio Design Forum Archive

I have both available to me for ceiling and wall panels. (3 pcf compressed glass or 4 pcf wool)
The mineral wool is way cheaper. Is there any pros/cons to using one over the other?

I would love to build the panels without frames, but basically have figured I would need to make frames for using the mineral wool because it appears to be more crumbly than fiberglass.

What has been you guys experiance afteractually working with the 2 different products?

Tom

tmix,

This maybe seems as a stupid approach.

Assuming you live in a spot where both materials are as easily available and accessible for the large public. (otherwise other market phenomena come into play)

Both rockwool and fiberglass are direct competitors of one another aiming at the same thermal market, which is still (normally) the main market for those guys.

For the same functionality those prices will be relative close together.
And this functionality is gasflow resistance, which is as well very defining for thermal insulation as for acoustic absorption.

rockwool is mostly (by the used raw materials) heavier (better: denser) for the same functionality.
Hence per weight unit rockwool will be cheaper, but not necessarily for the same functionality (read gasflow resistance).

This however depends also about region (used raw materials) and production process.
I recently heard that 3 pcf fibreglass of Certainteed feels and works different than 3 pcf OC.

In practice however for use in walls lower density can be an advantage (as per Brian Ravnaas extensive comparisons). In other situations it can be different.
I expect this 4 pcf rockwool to have lower gasflow resistance than this 3 pcf fibreglass.

Both materials are perfectly alright, it's just a matter of choosing a suitable type. And indeed mostly rockwool is more brittle (crumbling) than fiberglass which is more elastic.

To make a long story short:
Search for measurements to compare stuff:
A good starting point is Bob's page at:
http://www.bobgolds.com/AbsorptionCoefficients.htm

But even with small differences in absorption (with question marks) prices are a very important dominant factor.

Without checking: I thought Steve had entered this link already in one of his stickies.

Thank you Eric.

Price is indeed becoming an important factor. The studio is costing more than I planned.

I dont want to only consider the purchase price though, and my thoughts move towards longevity and function. I wonder if one product is more durable than the other. I wonder if shedding over the long haul is more prevalent with mineral wool. I want to build the panels to hang from the walls and ceilings in little or no frames, so I wonder if the wool will become big sacks of lint over the next few years?

I will probably be putting up the equivelant of about 70 - 80 pieces of 2x4 2" thick material , so I am hoping the shear number of panels with offset minor differences in performances.

I would love it if someone would share their experiances of their choices. Whether they would do it different. Again.. primarily for hanging absorbers.

Thanks again!

Tom

tmix wrote: The studio is costing more than I planned.

Tom,

This is the only common standard I know in studio projects. Hence you're on the right track...

You really can buy the cheaper stuff you know. If it works OK when you use it, don't use those panels to play ball with, don't use them for underwater acoustics, then they will live to see you become 100 years.
The main difference is when you push your fingers in rockwool, more chance it won't restore that well than more elastic fibreglass.

BTW: I used both in all types and kinds for lots of different applications with truckloads.

(he he he) Yep the money is always more than you think.

Thanks Eric,
I do really appreciate your help. It has given me peace about using the mineral wool. Once it is in place, nothing should be bothering it.

Thank you very much.

Off to build!

Tom