Fabric for bass traps/absorbers

[coplinger]

I'm going to be building some bass traps, wall mounted absorbers, & gobos. To anyone who has done this before, what do you use for fabric on the outside? Where do you source it? I'm hoping for something that's effective, but not too pricey. On a side note, there's a lot out there on building wall mounted absorbers, but not much on free standing gobos. Are the principals the same here? Would a gobo benefit from a plywood core with fiberglass on either side rather than just fiberglass in the center?

[Colorblind]

Not sure where you're located, but I bought all my absorber coverings at Fabricland. As a general rule, if you can breathe through it, it's acceptable. There are higher end products out there like the Guilford of Maine stuff, but not totally necessary IMO, especially if you're on a budget.

If you intend to use the gobos for isolation between sound sources in the same room, then yes, some mass in the middle can definitely help with that. In most cases, standard wall mounted absorbers are just some absorptive material (rigid fiberglass, mineral wool, etc.) with a frame around it, covered in fabric. No need for additional mass in the middle.

[MoreSpaceEcho]

The GoM fabric...you'd have to be a millionaire.

I got the fabric for my place either from a local shop or here:

https://www.atsacoustics.com/cat--DIY-A ... --102.html

The microsuede looks really nice IMO. Not cheap but still less than the GoM.

[digitaldrummer]

one of the advantages to the GoM is that I believe it is fire-retardant. in a commercial environment, that can be really important (or required by law).
in my private studio, I found that black cotton bed sheets from Walmart were actually less-expensive than buying similar cotton bulk fabric. I've used it to cover both wall-hanging absorption, super-chunks, and free-standing Gobos. And for the Gobos I constructed, they just have 4" thick of OC703 inside them.

[MoreSpaceEcho]

one of the advantages to the GoM is that I believe it is fire-retardant. in a commercial environment, that can be really important (or required by law).

Yes. Very good point!

[floid]

How does treating fabric with flame retardant spray compare to fabric that is flame retardant?

[losthighway]

How does treating fabric with flame retardant spray compare to fabric that is flame retardant?

Flame retardant spray gives you cancer. Some fabrics burn faster than other building materials, some similarly, some melt.

[The Scum]

If you're being inspected by the fire marshall as a commercial entity, they'll recognize Guilford, since it's what office cubicles are wrapped in. Guilford will also provide a fire certificate if you ask when you order.

It's spendy, but I've found them to be pretty easy to deal with - I called the 800 number and they overnighted a swatch booklet. They also shipped giant bolts from Maine to Colordao in about 5 days, even during covid times.

701 is also 66" wide, wider than a lot of typical bolts, so perhaps a little easier to cover big items with. It also comes in 1000 different shades of beige.

The self treatment stuff I've seen was more like dying the fabric - you fill a vat and it soaks in. And no certificates on the completed result.

For less expensive fire rated fabric, Acoustimac.com has an in-house variant, but in pretty basic colors.

If you don't need the fire rating, check out Big Duck Canvas Warehouse.

[losthighway]

^ This advice is so helpful I hope it comes up for someone else searching here for fabric advice in a few years. I want to like, highlight it in bold.

[vvv]

1000 different shades of beige

Gonna be the name of my dad rock band, that.

[The Scum]

I completely bypassed the gobo question, too.

Gobos are better with something solid at their heart. A sheet of 703 doesn't stop much sound from going through, a sheet of plywood does. Or a reclaimed solid-core door slab.

The ol' Jeff Cooper studio design book has a gobo design that's got 2 layers of 1/2" plywood, 2 layers of fiberglass, with 5/8" drywall to augment.

[Scodiddly]

You can use Borax as a flame retardant on cotton fabrics.

[coplinger]

Good tip thx! Would that be good enough to pass fire inspection?

[drumsound]

My 'issue' with GoM and all of the burlap looking things is that, no matter the color, its just visually unattractive. I'd really like to at least do the wall with the window in my booth in crushed velvet.

[Scodiddly]

Good tip thx! Would that be good enough to pass fire inspection?

I would imagine that it depends on your AHJ (Authority Having Jurisdiction). It would likely be a good thing to find out what their particulars might be before you stand an inspection, though.