I'm gonna build an iso room for guitars and amps, and I want to use some wood instead of drywall. Mostly for aesthetic reasons, but if I can get some acoustic benefit as well....
Quick rundown of the room: Large room is 25'x 30'x 12'H. Iso will be roughly 13'W, 17'L, 12'H in one corner of the room. Room within a room, two walls are brick covered with plaster, two will be freestanding. The freestanding will be double wall, 2x4 with space between -Drywall outside,isulation, gap, insulation, and 5/8 rough cut plywood inside. Then on the two masonry walls I planned on appying styrofoam, then a 2x4 insulated wall with the 1x8 pine boards.
Would it benefit me more acoustically to leave some gaps between the boards? Would this get me some absorbtion? Is there a certain size gap to use? I have enough of each material to do half of the room, so should I go half way up every wall with plywood, then the rest 1x8?
1x8's instead of drywall?
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NeglectedFred
- pushin' record
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Have you considered mineral board between studs and whatever wood you're planning to use?
I was affraid styrofoam could rattle, so I stuck with regular ol' insulation.
As far as leaving gaps, that's more diffusion than absorption. There have been studies done that have proven that random placements are equally as effective as mathmatical configurations. I'm sure people will disagree, though.
I think you will want some treatment, whatever you do.. Sometiong to absorb.
I was affraid styrofoam could rattle, so I stuck with regular ol' insulation.
As far as leaving gaps, that's more diffusion than absorption. There have been studies done that have proven that random placements are equally as effective as mathmatical configurations. I'm sure people will disagree, though.
I think you will want some treatment, whatever you do.. Sometiong to absorb.
I eat glue.
Leaving gaps will create slot resonators, a form of a helmholtz resonator. This is a type of absorption, not diffusion.
If you put drywall on one side of one wall, and 1x8 rough cut lumber on the inside of the other, and seal everything up tightly (with caulk), you'll get a 2-leaf system and maximum isolation.
HOWEVER, if you don't seal up the wood, and leave gaps, you'll lose a ton of isolation.
What I'd suggest is for your inner leaf, build "inside-out walls" (see John Sayers design on his forum), using the sheetrock on the outside of the inner wall and the 1x8s inside, with insulation between the studs. You will want to calculate the effective frequency range of each absorber, which is measured by the gap spacing between slats, internal volume of each resonator (ie, the airspace between each stud will act as its own resonator), and the depth of each slat (ie, 3/4" if it's 1x8 lumber).
There is some debate as to whether an inside-out-wall counts as a one-leaf or two-leaf design in itself (so you'd have either a 2-leaf total (good), or 3-leaf total (not so good) when the outer framing is taken into account.
My suggestion would be to hire a studio designer to work all this out for you, or be prepared to do a LOT of research on how to implement this correctly. Both the sound inside the booth and the levels of isolation you achieve are at stake, you want to do this right.
If you put drywall on one side of one wall, and 1x8 rough cut lumber on the inside of the other, and seal everything up tightly (with caulk), you'll get a 2-leaf system and maximum isolation.
HOWEVER, if you don't seal up the wood, and leave gaps, you'll lose a ton of isolation.
What I'd suggest is for your inner leaf, build "inside-out walls" (see John Sayers design on his forum), using the sheetrock on the outside of the inner wall and the 1x8s inside, with insulation between the studs. You will want to calculate the effective frequency range of each absorber, which is measured by the gap spacing between slats, internal volume of each resonator (ie, the airspace between each stud will act as its own resonator), and the depth of each slat (ie, 3/4" if it's 1x8 lumber).
There is some debate as to whether an inside-out-wall counts as a one-leaf or two-leaf design in itself (so you'd have either a 2-leaf total (good), or 3-leaf total (not so good) when the outer framing is taken into account.
My suggestion would be to hire a studio designer to work all this out for you, or be prepared to do a LOT of research on how to implement this correctly. Both the sound inside the booth and the levels of isolation you achieve are at stake, you want to do this right.
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DrummerMan
- george martin
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I could be wrong about this but I'm pretty sure that in terms of isolation, wood will not perform as well drywall. If you leave spaces between, the sound will travel to your brick/plaster walls and voila! flanking paths right out into your main room. Even if you perfectly seal up between planks, it is just not as dense. I was reminded recently of the difference when I picked up a crapload of 1/2" sheetrock and some 1/2" chipboard. the weight difference between the two was incredible. Granted, a 1x8 ends up being, I believe, 3/4" thick in reality, which is a touch thicker than your standard 5/8" sheetrock, but I still don't think it will isolate that well, if, in fact, isolation is a priority.
You could put up a layer of drywall on the inside, then put wood panels over it, to be more aesthetically pleasing. I'm pretty sure though that wood doesn't have any acoustic benefits, as a flat wall, to drywall. If you wanted to make a slat resonator, I'd seal up the room in standard drywall fashion, THEN apply whatever internal acoustic treatments were needed. If it were me.
You could put up a layer of drywall on the inside, then put wood panels over it, to be more aesthetically pleasing. I'm pretty sure though that wood doesn't have any acoustic benefits, as a flat wall, to drywall. If you wanted to make a slat resonator, I'd seal up the room in standard drywall fashion, THEN apply whatever internal acoustic treatments were needed. If it were me.
Thanks for the replys.
I knew I wasn't gonna get diffusion from this... I guess I should've explained better.
I have a large room 25x30 all brick with plaster, in one corner I'm building a room.
The two existing (brick, exterior) walls will get the styrofoam for heat and moisture reasons, not sound. Then put up 2x4's with insulation (fluffy side out), cover with fabric, then apply 1x8's with as yet to be determined gaps.
I've got enough isolation with the existing brick walls, so these two will be concerned primarily with aesthetics and sound quality.
On the two walls yet to exist: Double wall construction with drywall outside, gap, plywood inside (mass, air, mass). These will need some iso, so I could even drywall the inside, then put the wood up over it.
My main question is how to go about tuning the absorbant walls or is there any need? Would it just be broad band like a corner trap?
Is there a formula for what you were saying I should calculate JWL?
I realize more treatment will probably be necessary, but if I can squeeze some in during construction, why not?
If this won't work for absorbtion then I'll just nix the gaps and treat the room in the standard way.
I knew I wasn't gonna get diffusion from this... I guess I should've explained better.
I have a large room 25x30 all brick with plaster, in one corner I'm building a room.
The two existing (brick, exterior) walls will get the styrofoam for heat and moisture reasons, not sound. Then put up 2x4's with insulation (fluffy side out), cover with fabric, then apply 1x8's with as yet to be determined gaps.
I've got enough isolation with the existing brick walls, so these two will be concerned primarily with aesthetics and sound quality.
On the two walls yet to exist: Double wall construction with drywall outside, gap, plywood inside (mass, air, mass). These will need some iso, so I could even drywall the inside, then put the wood up over it.
My main question is how to go about tuning the absorbant walls or is there any need? Would it just be broad band like a corner trap?
Is there a formula for what you were saying I should calculate JWL?
I realize more treatment will probably be necessary, but if I can squeeze some in during construction, why not?
If this won't work for absorbtion then I'll just nix the gaps and treat the room in the standard way.
How would I go about posting a google sketchup drawing of this?
Thanks again for the help guys! I've read the Gervais book and the carpentry isn't a problem, but I just want to get the most sonic benefit out of the room. It's a quiet little ghost town by the way, so my only outside noise is when the garbage truck comes!
Thanks again for the help guys! I've read the Gervais book and the carpentry isn't a problem, but I just want to get the most sonic benefit out of the room. It's a quiet little ghost town by the way, so my only outside noise is when the garbage truck comes!
Ok, a few points....
Drummerman, you are probably right, less isolation from 1x8 (certainly pine) than sheetrock. Isolation is all about mass and airtightness, and you are hurting yourself on both counts by using 1x8s rather than drywall.
That said, isolation isn't a concern.
If it were me, I'd definitely do the inside-out wall design. This way you can incorporate treatment within the wall structure itself.
A slot resonator is different from a broadband absorber.... think of it similarly to an EQ filter with a higher Q. A resonator will have a narrower effective "absorption bandwidth," but it will absorb more within that bandwidth. This is why calculating the effective range of the resonator (the equation is also in Rod's book) is so important, you want the increased absorption to help you, not hurt you. Find out what your room modes inside the booth will be, and make sure those are covered.
Also, if the booth is going to be a rectangle, I'd use the angled slot resonator design to break up higher frequency reflections. Actually, I'd probably aim all these reflections toward one far wall, and make that wall fully absorptive (ie, insulation covered by cloth, not a slot resonator).
Drummerman, you are probably right, less isolation from 1x8 (certainly pine) than sheetrock. Isolation is all about mass and airtightness, and you are hurting yourself on both counts by using 1x8s rather than drywall.
That said, isolation isn't a concern.
If it were me, I'd definitely do the inside-out wall design. This way you can incorporate treatment within the wall structure itself.
A slot resonator is different from a broadband absorber.... think of it similarly to an EQ filter with a higher Q. A resonator will have a narrower effective "absorption bandwidth," but it will absorb more within that bandwidth. This is why calculating the effective range of the resonator (the equation is also in Rod's book) is so important, you want the increased absorption to help you, not hurt you. Find out what your room modes inside the booth will be, and make sure those are covered.
Also, if the booth is going to be a rectangle, I'd use the angled slot resonator design to break up higher frequency reflections. Actually, I'd probably aim all these reflections toward one far wall, and make that wall fully absorptive (ie, insulation covered by cloth, not a slot resonator).
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dino
- takin' a dinner break
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[quote="JWL"]PS - styrofoam will give you no acoustic/sound benefit whatsoever, though it will help with heat retention (I assume, depending on its insulating properties).[/quote]
Plus it's highly flamable, gives off nasty fumes as it deteriorates, and is prone to growing black mold in high humidity. You can paint it with mold retardant latex like the kind used in a bathrooms, but I'd avoid styrofoam in general. Nasty stuff.
dino
Plus it's highly flamable, gives off nasty fumes as it deteriorates, and is prone to growing black mold in high humidity. You can paint it with mold retardant latex like the kind used in a bathrooms, but I'd avoid styrofoam in general. Nasty stuff.
dino
I'd gladly trade everything I have now for a nice sounding room and a bucket of 57's
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