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Discussion Starter · #1 ·
Hey everyone. Due to some echoing problems my space has, I'm going to be making 8 absorption panels for my living room in the next few weeks. I've watched countless videos on youtube, and there's one technique that I think will work best for me. It's seems to be the simplest, cheapest, and quickest. I'll be using 47"x23"x3" Roxul Safe n' Sound that I had to special order from Lowe's. I would've preferred to use Rockboard, but it's just not available in my area I guess. Anyway, the guy in the video seems to be using 2" thick material, in a 4" thick panel. He attaches a 2" thick spacer inside of the frame for the Roxul to rest on, so while the Roxul is flush with the front of the panel, the recommended 2" air gap is still in place behind the panel. This is my problem... Where I live, the Lowe's not only does not carry the Roxul I need, they don't a 5" thick piece of lumber for the 3" thick Roxul, to allow my 2" air gap between the wall and the back of the Roxul. So, since I'll have to use 4" thick framing for the 3" thick Safe n' Sound, would only a 1" air gap be sufficient? I really don't want to get into all kinds of weird cuts that need to be made, or have to buy extra materials to make it work. Simpler is better. Also, I'd really prefer not to have 8 panels sticking out from the walls more than 4" all over the room.
 

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Quote:
Originally Posted by prodigy1324  /t/1522246/diy-absorption-panels#post_24473695


Hey everyone. Due to some echoing problems my space has, I'm going to be making 8 absorption panels for my living room in the next few weeks. I've watched countless videos on youtube, and there's one technique that I think will work best for me. It's seems to be the simplest, cheapest, and quickest. I'll be using 47"x23"x3" Roxul Safe n' Sound that I had to special order from Lowe's. I would've preferred to use Rockboard, but it's just not available in my area I guess. Anyway, the guy in the video seems to be using 2" thick material, in a 4" thick panel. He attaches a 2" thick spacer inside of the frame for the Roxul to rest on, so while the Roxul is flush with the front of the panel, the recommended 2" air gap is still in place behind the panel. This is my problem... Where I live, the Lowe's not only does not carry the Roxul I need, they don't a 5" thick piece of lumber for the 3" thick Roxul, to allow my 2" air gap between the wall and the back of the Roxul. So, since I'll have to use 4" thick framing for the 3" thick Safe n' Sound, would only a 1" air gap be sufficient? I really don't want to get into all kinds of weird cuts that need to be made, or have to buy extra materials to make it work. Simpler is better. Also, I'd really prefer not to have 8 panels sticking out from the walls more than 4" all over the room.

The air gap is among other things, just a trick to turn air into something that is about as good of an absorber as the actual absorbent material.


Generally, if you use thicker absorbent material and a smaller air gap, there is no loss.


Of course if you have 3 inch Roxul, you could build a thicker frame, you could use a 3" air space, and get even better LF absorption.


There is a pretty good absorber modeling Excel spread sheet here,

http://www.whealy.com/acoustics/Porous.html


and you can use it to estimate the effects of various combinations of absorber and air.
 

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Discussion Starter · #4 ·

Quote:
Originally Posted by brandon_k_w  /t/1522246/diy-absorption-panels#post_24473735


Check out this guy's idea. You may have these metal braces at your Lowes, and it would be easy to have the absorption and air gap in between these braces with no odd cuts required.

http://www.avsforum.com/t/1518269/my-experimental-acoustic-treatment-project#post_24368369

I love the idea of a sturdy metal frame. No warping and no splinters! Great idea and thanks for the feedback. This seems to be labor intensive, however. And if it's $10 per frame, that will add up quickly. The pine furring boards that I've got in mind will cost something like 3-4$ per panel. Plus I can see myself easily cutting a finger off while trying to work with metal. But like I said, that's a great idea and I bet he's quite happy with how they turned out.
 

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Discussion Starter · #5 ·

Quote:
Originally Posted by arnyk  /t/1522246/diy-absorption-panels#post_24473827


The air gap is among other things, just a trick to turn air into something that is about as good of an absorber as the actual absorbent material.


Generally, if you use thicker absorbent material and a smaller air gap, there is no loss.


Of course if you have 3 inch Roxul, you could build a thicker frame, you could use a 3" air space, and get even better LF absorption.


There is a pretty good absorber modeling Excel spread sheet here,

http://www.whealy.com/acoustics/Porous.html


and you can use it to estimate the effects of various combinations of absorber and air.

Ahh, thanks for the idea and the link to this calculator! I would love to use thicker material and have thicker panels, but I'd really like to avoid having 8 panels all sticking out so far. The added material and wood thickness would also make me concerned that weight would become an issue. I've been toying with the notion of getting an Auralex GRAMMA stand for my sub to help out with the LFE, but from what I've read about them, it only helps certain people out with certain circumstances... mainly upstairs/downstairs neighbours. I'm in a house, so that wouldn't be an issue, but if it takes care of some of the rattles I have throughout the room during certain frequencies, then it would pay for itself in no time.


Thanks again!
 

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This may help you visualize the "air gap advantage", so going 3" with 3" air gap you'd be down to 450hz, above the Fs 250hz by strictly 1/4 wavelength theory, but you'd still absorb down lower just not fully.
http://www.avsforum.com/t/1312693/diy-construction-methods-of-hang-able-acoustic-panels-moveable-corner-traps-not-fixed-frames/120#post_24030967



Here's how I put an air gap for my panels:
http://www.avsforum.com/t/1312693/diy-construction-methods-of-hang-able-acoustic-panels-moveable-corner-traps-not-fixed-frames/120#post_24030967
Quote:
Originally Posted by mtbdudex  /t/1312693/diy-construction-methods...e-corner-traps-not-fixed-frames#post_19947658


Hanging 101 for DIY framed 2' x 4' acoustic panels:


I used alum "z" from ats acoustics, http://www.atsacoustics.com/item--ac...are--IK12.html
.



They were set 3" in from each frame edge to have invisible look and the frame sorta just float there.

Note:

Wall to frame spacer/holders were pre-made, pre-drilled (each then acts as its own drill jig for holes into the wall), and painted wall color prior.


Mine were 19" wide and 3 1/2 tall, and 1 1/2 inches thick, basically scrap stuff I had lying around.

Measure twice, use blue tape for visual markers, locate top holder, mine was a 1 1/2" thick piece so the panel would have 2" air gap.


Hold with hand, drill into drywall with 3" deck screw, mini-level assures level, Locate bottom holder, drill into drywall with 3" deck screw.
.



Remove, use drilled holes to locate the 50lb plastic dywall anchors



Re-attach top/bottom holders, using 3" deck screw.
.



If measurements done correctly slight tweaks to get level----
.



this shows 2" air gap



I should say:


-the cloth wrapped fiberglass is nicely held rigid in, no worries about it ever coming out, even due to my kids possible "abuse".


That's why I made channels instead of just "boxing it in"....I was un-sure about the robustness of just that way.


-a 3 point mtg, 2 top and 1 bottom, is very secure and quite easy to locate and level, don't be concerned so much.


-the WAF is extremely high on these, she likes them!
 

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Quote:
Originally Posted by prodigy1324  /t/1522246/diy-absorption-panels#post_24474003

Quote:
Originally Posted by arnyk  /t/1522246/diy-absorption-panels#post_24473827


The air gap is among other things, just a trick to turn air into something that is about as good of an absorber as the actual absorbent material.


Generally, if you use thicker absorbent material and a smaller air gap, there is no loss.


Of course if you have 3 inch Roxul, you could build a thicker frame, you could use a 3" air space, and get even better LF absorption.


There is a pretty good absorber modeling Excel spread sheet here,

http://www.whealy.com/acoustics/Porous.html


and you can use it to estimate the effects of various combinations of absorber and air.

Ahh, thanks for the idea and the link to this calculator! I would love to use thicker material and have thicker panels, but I'd really like to avoid having 8 panels all sticking out so far. The added material and wood thickness would also make me concerned that weight would become an issue. I've been toying with the notion of getting an Auralex GRAMMA stand for my sub to help out with the LFE, but from what I've read about them, it only helps certain people out with certain circumstances... mainly upstairs/downstairs neighbours. I'm in a house, so that wouldn't be an issue, but if it takes care of some of the rattles I have throughout the room during certain frequencies, then it would pay for itself in no time.


Thanks again!

Just a geometric visual tip - frames don't seem to stick out so far in many cases if you angle the sides.




People may worry about covering up some of the area with wood, but usually the wood adds diffusion which is generally a good thing.


One of the rules of acoustics is that the three main elements of acoustics are reflection, absorption, and diffusion. There is a correct balance between them (roughly equal areas might be a good starting point), but the most expensive of the bunch is diffusion.
 

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Quote:
Originally Posted by arnyk  /t/1522246/diy-absorption-panels#post_24476472

 
Quote:
Originally Posted by prodigy1324  /t/1522246/diy-absorption-panels#post_24474003

Ahh, thanks for the idea and the link to this calculator! I would love to use thicker material and have thicker panels, but I'd really like to avoid having 8 panels all sticking out so far. The added material and wood thickness would also make me concerned that weight would become an issue.
 

What I have done when I made my panels was to drill 2 inch diameter holes in the wood with a hole saw. This not only allows the sound another route into the absorbing material but it makes the frames substantially lighter too.

 



 

 

If you prefer you can make even bigger weight savings by removing even more material as shown below in some experimental tri-corner traps I made. This does not compromise the structural integrity of the frame but will save huge amounts of weight.

 

 

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Quote:
Originally Posted by kbarnes701  /t/1522246/diy-absorption-panels#post_24476576

Quote:
Originally Posted by arnyk  /t/1522246/diy-absorption-panels#post_24476472


 
Quote:
Originally Posted by prodigy1324  /t/1522246/diy-absorption-panels#post_24474003





Ahh, thanks for the idea and the link to this calculator! I would love to use thicker material and have thicker panels, but I'd really like to avoid having 8 panels all sticking out so far. The added material and wood thickness would also make me concerned that weight would become an issue.

What I have done when I made my panels was to drill 2 inch diameter holes in the wood with a hole saw. This not only allows the sound another route into the absorbing material but it makes the frames substantially lighter too.






If you prefer you can make even bigger weight savings by removing even more material as shown below in some experimental tri-corner traps I made. This does not compromise the structural integrity of the frame but will save huge amounts of weight.



Very cool engineering!


On the worst day of its life this approach also adds diffusion.
 

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Quote:
Originally Posted by arnyk  /t/1522246/diy-absorption-panels#post_24476590

 
Quote:
Originally Posted by kbarnes701  /t/1522246/diy-absorption-panels#post_24476576
What I have done when I made my panels was to drill 2 inch diameter holes in the wood with a hole saw. This not only allows the sound another route into the absorbing material but it makes the frames substantially lighter too.




If you prefer you can make even bigger weight savings by removing even more material as shown below in some experimental tri-corner traps I made. This does not compromise the structural integrity of the frame but will save huge amounts of weight.


 

Very cool engineering!


On the worst day of its life this approach also adds diffusion.
 

Why thanks, Arny!  "Engineering" is something nobody has ever called my DIY efforts before :)  My DIY skills are very average, but the beauty of making acoustic panels is that all the 'manufacturing irregularities' are covered by fabric eventually and thus hidden from view, so no great care or precision is needed.

 

I heartily commend DIY treatments to anyone as they are so easy to make and cost a fraction of the commercially sold ones.  YouTube is also a mine of information in this respect, as is AVS of course.
 

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Discussion Starter · #12 ·

Quote:
Originally Posted by kbarnes701  /t/1522246/diy-absorption-panels#post_24476576


What I have done when I made my panels was to drill 2 inch diameter holes in the wood with a hole saw. This not only allows the sound another route into the absorbing material but it makes the frames substantially lighter too.






If you prefer you can make even bigger weight savings by removing even more material as shown below in some experimental tri-corner traps I made. This does not compromise the structural integrity of the frame but will save huge amounts of weight.



That's a fantastic idea! And cloth will cover it, so aesthetically it will still look good. What kind of wood did you use? Type, thickness, etc.
 

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Quote:
Originally Posted by myfipie  /t/1522246/diy-absorption-panels#post_24477014


We actually did a test on open frames vs closed frames. Does not seem to help with lower frequencies with the open sides.
http://www.gikacoustics.com/diy-acoustic-panel-frames/


Which ever way you do end up making them, make sure you straddle some (actually a lot) of corners. Low end is the largest problem in smaller rooms and panels like you are making work best in the corner.
http://www.gikacoustics.com/video_bass-traps/
 

I wasn't especially trying to improve things by cutting away part of the material, or even to change things - the primary consideration for me was to reduce the weight of the panel. As there isn’t much difference acoustically (to quote your article) then the weight saving seems to be worthwhile.

 

Quoted from your linked article:

 

"Our advice on the matter?  Constructing an extra panel or two is going to make a much larger difference acoustically than worrying about making them with or without frames. Get building! "

 

I designed my room with the help of Bryan Pape and subsequently by measuring with REW, so yes, corners are straddled etc :)  More than half my panels have been supplied by GIK here in the UK and I am very pleased with both the panels and the service. But once I realised that even with my limited DIY skills that I could build my own and save quite a lot of money, I dug out the tools, bought the materials and knuckled down to it. 

 

I have also found the info on your site to be very helpful too. Great stuff.
 

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Quote:
Originally Posted by prodigy1324  /t/1522246/diy-absorption-panels#post_24477094


That's a fantastic idea! And cloth will cover it, so aesthetically it will still look good. What kind of wood did you use? Type, thickness, etc.
 

I use a 4 inch thick slab of rockwool type material (we use different names in the UK for this stuff, and the brands are different, but the end result is the same if you do your homework before buying), and the panels I made were all designed to straddle corners so I didn’t worry too much about creating a large air gap behind the acoustic material. This means I used timber that was slightly over 4 inches wide (we use metric here so there is no such thing as 4 inches any more, unfortunately) and just bought it in suitable lengths for the best deal on price. The panels are nominally 48 inches x 24 inches, the same as the rockwool slabs. I just bought the cheapest planed timber that the merchant had in stock.  The timber is about half an inch thick - 18mm IIRC which is just over half an inch but half an inch is fine. There's no need for huge structural strength in these things. If you are going to hang the panels on the wall, I'd suggest you go for wider timber than 4 inches so that you can create an air gap once the rockwool is in place.

 

I just did simple butt joints for the timber frames, glued and screwed. This gives a fine result for strength and there is no need for corner bracing. I let the glue dry overnight. I then sanded the joints to make sure they were smooth and wouldn't snag the fabric later. One tip I learned after my first panel was to slightly round off every corner, including along the lengths of the panels as well as the obvious corners, because when you stretch the fabric nice and tight over the frame, you can find that any sharp edges on corners will tend to poke through the fabric.

 

I used Camira Cara fabric which is the same as GIK used for my other panels, to match them but you can use other acoustically transparent cloth. Just get a decent staple gun and a LOT of staples and covering the panels is real easy. For the corner fold I copied the GIK method but you will figure that out by trial and error before you staple.

 

As with everything, experience comes into play and you will find that the construction improves after your first one that you make but all of mine were very successful and very straightforward. And as you say, the fabric covers a multitude of construction sins.

 

Bottom line: if I can do this on my garage f;oor, using common tools, then anyone can. Go for it!  Treatments are the biggest improvement you can make to the sound, and one of the cheapest when you DIY.

 

EDIT: I forgot to add that once you have put the rockwool into the frame, with the frame laying on the fabric, you will need to staple some cheap AT fabric into the back side of the frame to hold the rockwool in place at the rear. You can use any quality and color for this as the back sides will never be seen - no need to use expensive Camira etc. Just make sure it is AT.

 

These pics might make it more clear what I am saying there:

 



 



 

 

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Quote:
I designed my room with the help of Bryan Pape and subsequently by measuring with REW, so yes, corners are straddled etc

Glad we could be of service to you.
 

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Discussion Starter · #16 ·

Quote:
Originally Posted by kbarnes701  /t/1522246/diy-absorption-panels#post_24477168


I use a 4 inch thick slab of rockwool type material (we use different names in the UK for this stuff, and the brands are different, but the end result is the same if you do your homework before buying), and the panels I made were all designed to straddle corners so I didn’t worry too much about creating a large air gap behind the acoustic material. This means I used timber that was slightly over 4 inches wide (we use metric here so there is no such thing as 4 inches any more, unfortunately) and just bought it in suitable lengths for the best deal on price. The panels are nominally 48 inches x 24 inches, the same as the rockwool slabs. I just bought the cheapest planed timber that the merchant had in stock.  The timber is about half an inch thick - 18mm IIRC which is just over half an inch but half an inch is fine. There's no need for huge structural strength in these things. If you are going to hang the panels on the wall, I'd suggest you go for wider timber than 4 inches so that you can create an air gap once the rockwool is in place.


I just did simple butt joints for the timber frames, glued and screwed. This gives a fine result for strength and there is no need for corner bracing. I let the glue dry overnight. I then sanded the joints to make sure they were smooth and wouldn't snag the fabric later. One tip I learned after my first panel was to slightly round off every corner, including along the lengths of the panels as well as the obvious corners, because when you stretch the fabric nice and tight over the frame, you can find that any sharp edges on corners will tend to poke through the fabric.


I used Camira Cara fabric which is the same as GIK used for my other panels, to match them but you can use other acoustically transparent cloth. Just get a decent staple gun and a LOT of staples and covering the panels is real easy. For the corner fold I copied the GIK method but you will figure that out by trial and error before you staple.


As with everything, experience comes into play and you will find that the construction improves after your first one that you make but all of mine were very successful and very straightforward. And as you say, the fabric covers a multitude of construction sins.


Bottom line: if I can do this on my garage f;oor, using common tools, then anyone can. Go for it!  Treatments are the biggest improvement you can make to the sound, and one of the cheapest when you DIY.

Yes, I'm expecting a huge improvement in overall sound quality and echo reduction. I have wood floors and 8' ceilings with relatively nothing hanging on the walls. So naturally, it sounds a bit like sitting inside of a tin can. I did lay an 8'x10' area rug with helped substantially, but the lack of having any wall acoustic treatments has been weighing heavily on my mind lately.


Great ideas about rounding the corners and edges before applying the fabric. I can see the fabric getting hung up and tearing, and me getting pissed and going into full rampage mode. I don't have an air compressor, so of course I don't have an air nail gun. I do however have an electric one that is capable of shooting 5/8" brads. So that is what I will use when attaching the fabric.


As far as connecting the boards themselves, I'll have to either screw them in or nail them in by hand. It depends on the wood, and I'm leaning towards cedar fence boards right now, due to their size, strength, cost, and low weight. I talked to a carpenter buddy of mine last night about it, and he advised me that should I start having problems with the wood splitting from nailing the boards together, an old carpenter's trick is to first slightly dull the point on the nail so it's not quite so sharp. Sounds crazy, but apparently it works. Just one of those things, I guess.


Anyway, I really like your idea of using a hole saw and reducing some of the weight that way. So, a 2" hole saw be on my list of goodies to pick up from the hardware store. I'll have to research the Camira Cara cloth you mentioned. I haven't heard of it and it may not be available here. I was thinking about going with this stuff called Broadcloth, which is evidently quite cheap, readily available, and acoustically transparent. Someone mentioned dyed burlap, so I might look into that as well. Since I'm not using straight up fibreglass, I'm not too concerned with toxic particles seeping out of the panels.


Thanks again, buddy!
 

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Quote:
Originally Posted by myfipie  /t/1522246/diy-absorption-panels#post_24477194

 
Quote:
I designed my room with the help of Bryan Pape and subsequently by measuring with REW, so yes, corners are straddled etc

Glad we could be of service to you.
 

Oh yes - definitely. Bryan is a man of much patience and gave me all the initial info I needed to get started with treating the room.
 

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Quote:
Originally Posted by prodigy1324  /t/1522246/diy-absorption-panels#post_24477256
Thanks again, buddy!
 

You’re welcome. I just added three pics to that last post, in case you missed them. I think you figured out what I was trying to say though. 

 

Any AT cloth will be OK. I only used Camira because it's what GIK used and I wanted them all to match. I have about 22 panels in the HT.
 

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Quote:
Originally Posted by kbarnes701  /t/1522246/diy-absorption-panels#post_24477269


Oh yes - definitely. Bryan is a man of much patience and gave me all the initial info I needed to get started with treating the room.

Thanks. Part of the value of buying a finished product.




BTW you did a great job on your build of the panels.
 

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Quote:
Originally Posted by myfipie  /t/1522246/diy-absorption-panels#post_24477314

 
Quote:
Originally Posted by kbarnes701  /t/1522246/diy-absorption-panels#post_24477269


Oh yes - definitely. Bryan is a man of much patience and gave me all the initial info I needed to get started with treating the room.

Thanks. Part of the value of buying a finished product.


 
 

Oh yes. I did buy quite a few from your UK operation :)

 
Quote:
 BTW you did a great job on your build of the panels.
 

Thank you!  That is great to hear!
 
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