Pssst, Buddy, Got Any Rockwool?

[Audiowonderland]

Originally Posted by KevinH

I'm thinking about building some acoustic panels using Rockwool. But Rockwool Comfortboard isn't available at my local big box stores or building suppliers. I spoke with a large insulation supplier and was told that Rockwool is in high demand, currently overpriced because of that, and has a 2-3 month wait time. The price estimate I got was $3.15 (USD)/s.f. for 2" Rockwool 80. One pack would run $130, which would make 2.5 panels 2'x4'x4". That works out to $52/panel for the filler.

Then add in the cost of lumber, which is still pretty crazy, and fabric and the $88/panel that ATS charges for its 2'x4'x4" panels seems like a good deal. For those of you that built your own panels, did you find Rockwool cheaper somewhere, or use an alternate material?

Last I looked they had it at Lowes..

https://www.lowes.com/pd/ROCKWOOL-SA...xtracted=false

[Rudy4]

I don't have gobos, but in looking around I thought the Primacoustic GoTrap gobos as sold by Sweetwater looked like they might work well in a home studio.

They are 24" by 36" by 8" boxes and stackable. Expensive, but they could be copied inexpensively by those handy with woodworking projects. With a bit of thought, boxes could be made to use a double layer of the less expensive and readily available fill material. The box sides could be cut from 3/4" birch plywood and finger jointed for a solidly built box.

Stackable boxes would be nice because they could be stacked against an outer wall when not needed as gobos and still add unobtrusive sound control.

[jim1960]

Originally Posted by Rudy4

I don't have gobos, but in looking around I thought the Primacoustic GoTrap gobos as sold by Sweetwater looked like they might work well in a home studio.

For the price of one Primacoustic GoTrap you could get three 24"x48" Monster Bass Traps from GIK. And those panels are more effective that the GoTrap.

[KevinH]

Originally Posted by Chipotle

Just be aware that Rockwool Safe-n-Sound is *not* the same stuff as the Rockwool 60 (which I think is called Rockboard 60 now). Safe-n-Sound, which is the stuff you can get at the big boxes, is less than half as dense (38 kg/m3 vs 96 kg/m3 for 60), so you need greater thickness for the same result...

Good point. Here are some absorption coefficients. Top two entries seem to be easy to get at Lowes, etc., but evidently aren't as good as the Rockboard at low frequencies.

sacc.jpg

though the significance of that I'm sure depends on the room. And I recall reading somewhere that differences in the coefficient of 0.15 are not significant. I'm not sure if that's measurement uncertainty, or significant in being able to hear a difference.

Originally Posted by b1j

...However, it does look like 4” thick Rockboard 40 would have a much higher Noise Reduction Coefficient at 125 Hz than Safe n Sound at 3”...


But can you find it?

Yeah, finding it is the problem. You can find it online at ATS Acoustics or GIK Acoustics, but the shipping isn't cheap.

Originally Posted by KevWind

I would recommend at least four -2' X 4' panels for a free standing gobos in V shapes

If sourcing is difficult You might want to look into GIK they are now using Knuaf Ecose and for DIY they sell packs of 6 ---2" by 24" ft by 48" ft for $46.80. don't know if that includes shipping ?
https://www.gikacoustics.com/product...rglass-1-6-lb/
...

It doesn't. The shipping costs the same ($47, to me) as the panels, which works out to a total of $31/panel for the filler. But definitely better than the quote I was getting from my local Rockwool supplier.

[Acousticado]

I’m located in Eastern Ontario, Canada. As of today, I’ve been able to locally source RockWool Rockboard 60 and have received a quote. The cost (tax incl.) per bag of 7 panels @ 2’x4’x2” (56 sq/ft) is Cdn$178.50 ($25.50/panel)/US$127.25 ($18.17/panel) (approx.). The problem is, I have to buy a minimum of 1 skid of 14 bags. I only need 2, so unfortunately I can’t do that. And, ETA is 120 days (not a problem for that).

Small world...turns out that the sales manager who provided me with the quote is someone whose parents and him, I knew in my community back in the 90s. In fact, we were part of a group of couples for a time. He’s told me to call him tomorrow to discuss figuring something out.

I doubt he’s going to be able to sell me just 2 bags and I don’t know any local guys who’d want to participate, so likely I won’t be able to get any of the Rockboard 60. If I can’t, I suppose I’ll have to get some Comfortboard or Safe ‘n Sound, both which are easy to get locally.

My fingers are crossed.

p.s. Does anyone know if the Rockboard 60 is rigid enough to fabricate panels simply by directly wrapping suitable fabric using an adhesive, rather than constructing a light frame such as is required if using Comfortboard or S’nS?

[b1j]

Two observations:

1) From what I’ve seen, Rockboard is rigid enough to hold together inside a cloth wrapping — maybe not for a gobo but as a wall hanging. Safe n Sound is floppy and needs a rigid frame.

2) The manufacturer of Rockwool is either ignoring the studio treatment market or has run the numbers and deemed it unprofitable for them. This explains to me the business plan of the few commercial panel suppliers: buy in bulk and draw down inventory. If I were selling dozens of panels a month, I could buy at these quantities.

On a home studio basis, we can’t do that. Maybe AGF could pool its resources and buy a commercial-sized quantity, and distribute it at cost to members who want a single 8-pack (or 12-pack of 16”)?

There’s still that shipping cost, though, so maybe it could work on regional basis?

But still, the price Acousticado quoted is still high when compared with the $11/batt I found for 3” Safe n Sound. Maybe the savings on frame material cost and labor even things out.

[Acousticado]

Originally Posted by b1j

...Maybe AGF could pool its resources and buy a commercial-sized quantity, and distribute it at cost to members who want a single 8-pack (or 12-pack of 16”)?

There’s still that shipping cost, though, so maybe it could work on regional basis?...

Unfortunately, I can’t think of any way an initiative like that could work.

[Chipotle]

Originally Posted by b1j

2) The manufacturer of Rockwool is either ignoring the studio treatment market or has run the numbers and deemed it unprofitable for them. This explains to me the business plan of the few commercial panel suppliers: buy in bulk and draw down inventory.

It's not ignoring, it's the latter--it's not profitable to try to sell that product in small amounts at retail. The number of DIY acoustic panel makers is microscopic compared to construction contractors (or premade acoustic panel manufacturers) who buy wholesale, in quantity, year-round.

Have you looked for OC703? While it might be the same story, it also may be more available or at least more cost-effective. I managed to get a place to sell me just two packages (8 batts each) of 703, since I think they sold quite a bit to local construction companies. If I wanted Rockwool which they didn't normally carry, I'm sure the minimum size of the order would have been prohibitive.

Or, in the end, just by pre-made panels. After building a bunch of my own during the pandemic, lumber and insulation prices reached the point where the DIY savings just wasn't worth it. If you want an in-between solution, Acoustimac has kits - frame, insulation and fabric - that are a bit less expensive than a full pre-made panel. Easy to put together, and you can save a bit of money.

But shipping on large, heavy-ish stuff is going to be expensive no matter how you cut it. I had to order some acoustic panels for work, and needed one that was 6'x2'. The shipping for that size was ridiculous, like double the price of the panel itself. The salesperson suggested I order two 3'x2' panels instead, which cut the shipping cost by 60%! Needless to say, that's what we did.

[KevWind]

Originally Posted by b1j

Two observations:

1) From what I’ve seen, Rockboard is rigid enough to hold together inside a cloth wrapping — maybe not for a gobo but as a wall hanging. Safe n Sound is floppy and needs a rigid frame.

2) The manufacturer of Rockwool is either ignoring the studio treatment market or has run the numbers and deemed it unprofitable for them. This explains to me the business plan of the few commercial panel suppliers: buy in bulk and draw down inventory. If I were selling dozens of panels a month, I could buy at these quantities.

On a home studio basis, we can’t do that. Maybe AGF could pool its resources and buy a commercial-sized quantity, and distribute it at cost to members who want a single 8-pack (or 12-pack of 16”)?

There’s still that shipping cost, though, so maybe it could work on regional basis?

But still, the price Acousticado quoted is still high when compared with the $11/batt I found for 3” Safe n Sound. Maybe the savings on frame material cost and labor even things out.

Well first it's not ignoring nor running the numbers on the part of Rockwool etc. . Selling direct to consumers is simply not in the business plan of Mfg's of insulation. The numbers they produce preclude shipping in anything less than either container or semi-trailer loads to distributers, who then either sell direct like (Home Depot et.al.) or the distributors sell to retailers who sell to public like lumber yards ...

[phcorrigan]

Originally Posted by keith.rogers

You do need a power miter saw to make good cuts that will let you just cut and screw the frame pieces together and have them be square and not twisty.

You can also use a Swanson Speed Square (https://a.co/d/biEtkxQ) or similar as a cutting guide to get a good square end.

[Aspiring]

Originally Posted by phcorrigan

You can also use a Swanson Speed Square (https://a.co/d/biEtkxQ) or similar as a cutting guide to get a good square end.

Lots of ways to do it for sure. Compound miter is great. I also have a Bosch track saw with a calibrated angle guide that does a great job for square ends

[Acousticado]

Today, I spoke with the sales manager at the local RockWool supplier I mentioned in my post above. Given my small need, unfortunately, getting the Rockboard 60 isn’t going to work out. He told me he can get me Comfortboard 110, but looking at the specs, it seems to me there are better RW performers. In fact, after comparing the specs for S’n’S, RB 40 & 60, and CB 80 & 110, the 3” S’n’S actually seems like the best option. I hope to soon get at building the frames for wall/ceiling panels, corner bass traps and a 3-panel gobo. I’ll be following this method.

[b1j]

Originally Posted by Acousticado

Today, I spoke with the sales manager at the local RockWool supplier I mentioned in my post above. Given my small need, unfortunately, getting the Rockboard 60 isn’t going to work out. He told me he can get me Comfortboard 110, but looking at the specs, it seems to me there are better RW performers. In fact, after comparing the specs for S’n’S, RB 40 & 60, and CB 80 & 110, the 3” S’n’S actually seems like the best option. I hope to soon get at building the frames for wall/ceiling panels, corner bass traps and a 3-panel gobo. I’ll be following this method.

I’m pulling for you, Tom. Another builder following in Michael Wynne’s footsteps. Mine turned out great, after I worked out a few kinks. Pop me a PM if you want to talk about any of the steps.

[Audiowonderland]

Originally Posted by Acousticado

Today, I spoke with the sales manager at the local RockWool supplier I mentioned in my post above. Given my small need, unfortunately, getting the Rockboard 60 isn’t going to work out. He told me he can get me Comfortboard 110, but looking at the specs, it seems to me there are better RW performers. In fact, after comparing the specs for S’n’S, RB 40 & 60, and CB 80 & 110, the 3” S’n’S actually seems like the best option. I hope to soon get at building the frames for wall/ceiling panels, corner bass traps and a 3-panel gobo. I’ll be following this method.

I doubled them up and built 6" absorbers and space them 6" off the wall in my live room. The "control room" is a mess acoustically. I bought 3 wire racks/shelfs from Lowes and filled them top to bottom with Safe n Sound. They are 4' wide, ~6.5' tall and 15" deep. The ultimate super chunks. All are on wheels so I can have behind and beside for critical listening and can be moved back when I need a bit more room for tracking other players

The stuff works well

[Acousticado]

Originally Posted by b1j

I’m pulling for you, Tom. Another builder following in Michael Wynne’s footsteps. Mine turned out great, after I worked out a few kinks. Pop me a PM if you want to talk about any of the steps.

Thank you! I have followed your journey with interest.

Planning the construction, I’ll buy the two bags of S’n’S I’ll need overall, but just enough frame build material to produce one panel, minus the fabric wrap. I won’t be having any visible wood framing, it’ll all be wrapped in fabric (except possibly for the portable gobo panels requiring more robust pine structure). If the framing build goes well, I’ll buy the rest of the wood material and construct the panels in an assembly line approach...cut all the back framing pieces, then cut all the side/end pieces, then assemble all of it, one by one. Then, likely I’ll buy just enough of whatever fabric I choose to try the wrap on one. To me, the look of the finish is important. If the wrap looks professional enough, tight, flat with sharp corners, I’ll do the rest. If not, likely I’ll try to find an experienced upholsterer. Given that the materials won’t cost much, spending on a nice finish will be worth it.