Mineral wool options and combinations for bass traps

[SaSi_SiDi]

I am currently shopping for mineral wool to build the first corner traps for my listening room.

4" thick material is out of the question - nobody carries it and the few yards that can order that for me can't even quote a price let alone let me know the density.

I've been able to find the following in 2x4 ft dimensions.

3cm (1.25") thick at 100kg/m3 (about the same as 705)
5cm (2") thick at 45kg/m3 (about the same as 703).

The price for both types is good and although they don't have a facing, it's possible to attach it. The same store (Leroy Merlin) carries adhesive panels with FRK and 1/4" foam. Something tells me that the foam between the facing and the panels might help the facing vibrate more freely and absorb more low frequencies - but I may be wrong.

There has been lots of discussion on FRK alternatives and I am aware of them. However, how about a thin aluminium foil glued to 1/4" soft foam and then glued to the mineral wool panel?

[takman]

hey there...

first things things first...

dont worry about the 4"..you can combine two 2" panels together like i did.

get the 45 kg/3...thats what i have ( actually technically its 50kg/3)

this is the rockwool i used ( in greece its called stonewool but its exactly the same thing)

Fibran - Insulation Materials

its worked extremely well, i love the way my studio sounds...plus a person on here by the name of fabric audio in Athens is using it in his professional studio...just look in the photo diaries studio build section for his name

I paid 3 euro and 30 cents for 1 sheet of 120cm x 60cm ( 2' x 4')...yep its dirt cheap...at least that was the price the supplier was selling it for...i did all my panels for around 120 euros....

I know stonewool is available with FRK.....at least i am certain i saw it when i was buying stonewool...i dont know what density it was...i was planning on finding out soon because i have to build a few more panels and i wanted to use FRK.

I wouldnt go with the insulation with the foam under the FRK....dont believe its been tested, never heard of anyone using it either...unless someone know about it...

if you have anymore questions feel free to send me a PM..i live 3 hours away from Athens ( check out the link in my signature...got a vid coming soon too)

good luck

[SaSi_SiDi]

Hi, thanks for the response.

I know I can combine two sheets of 2" each to make the 4" depth. It's just so easier to *not* have to do that...

The stonewool I found was indeed a Fibran product - the brand name was Geowool.

The price for a pack of 10x2" sheets was 19 euro (about $30) which I find to be great, at least compared to other prices I've seen in yards.

[takman]

thats even cheaper than what paid....

putting two sheets together is easy..doesnt create any problems...unless you are bilding something different or unusual i suppose...

[SaSi_SiDi]

I brought 3 packs of 10x2" panels home yesterday. Dimensions are the normal 2 x 4ft (60x120cm).

I am planning to build two large corner traps, floor to ceiling. I will be needing 12 pieces to make that 4" thick.

I'm glad I got the 45kg/m3 version. A single pack of 10 pieces seems pretty heavy - I might need to rething the framing to use. The 100kg/m3 would probably be too heavy to handle by myself.

I will start a thread on how I expect these bass traps to look like and post pics of progress. They will look different from what I've seen so far.

[ButchP]

Originally Posted by SaSi_SiDi

...
The price for a pack of 10x2" sheets was 19 euro (about $30) which I find to be great, at least compared to other prices I've seen in yards.

Damn!! I wish I could find some that cheap in LA!!You could make a super chunks for way under $100!!

BP

[SaSi_SiDi]

Originally Posted by ButchP

Damn!! I wish I could find some that cheap in LA!!You could make a super chunks for way under $100!!

BP

Yes, you are right. At this price I am wondering if it would be better to cut each piece in two triangle halves and make solid corner superchunks.

[Glenn Kuras]

Originally Posted by SaSi_SiDi

Yes, you are right. At this price I am wondering if it would be better to cut each piece in two triangle halves and make solid corner superchunks.

Totally. I would go with filling the corner if possible. thumbsup

[SaSi_SiDi]

Doing the arithmetic:
3 packs of 10 pieces each at 59 euro give 60 half pieces, triangle shaped with two sides at 2x4ft.

I planned to have a corner trap at 260cm high, that gives 52 triangles to fill.

My 3 packs can make one corner trap and have 4 whole pieces to spare so I can deduce the price of the superchunk material to be ~50 euro.

I only have to worry about fitting a triangle support plywood to take the stuff - want to leave 2-3" on the floor free under that to allow for cables, etc - instead of building a frame for the trap and hanging it from the ceiling.

Also, I will need far less cloth to cover the trap - only for the face instead all around.

I will need to think on how to mount the cloth at the edges. Need to think about it - wasn't thinking to take this route.

And I also need to plan another trip to the store for another 3 packs of material. And I just removed the railings from the car's roof...