Week 16: Tutorial – How To Make Sound Absorption Acoustical Panels

This week I’m going to show you how to make the sound absorption acoustical panels I made for the studio a few months ago and wrote about in this post, which elaborates on the use and effectiveness of such panels.

I now have a small side business making these panels for others, using industry standard materials that look and perform beautifully. But today I’m going to give a tutorial on how to use less expensive materials in a way that will allow you to make some panels for yourself that still look great and are just as effective for controlling sound as the pro panels, at roughly half the price.

Now of course, professional panels are constructed well, are easy to install, and always come out looking top-notch because they’re made by people who with experience and with materials and processes that are paid for in bulk. But in all reality, they are fairly simple to build. So if you’re a little handy, have extra time and want to save a couple bucks, here’s how you do it!

And if you’d prefer, you can easily purchase professionally made panels at a guaranteed low price from the Inity Acoustics website.

Tools and Materials

First, let’s look at the necessary tools and materials. The tools you’ll need are fairly standard. Of course, if you have better tools you can save yourself a lot of time with some steps. But I’ll show you how to make these using tools many people already have at their disposal.

Tools:

Materials:

I’m going to list the materials needed to make 8 panels. I picked 8 because the sound absorption insulation I’m recommending comes in packages of 8. Here’s what you need.

  • Sound absorption core material. Recommended: Roxul Safe’n’Sound (3″ thick, 2’x4′ for wood studs, 24″ on center) – 1 package of 8 (Other options listed below. Compare noise reduction coefficients of various materials here.)
  • 1×3 framing lumber (8′ lengths) – 12 pieces (make sure they’re straight!)
  • 1/4″ sheets of plywood (4’x8′) – 2 sheets – get these cut to 2’x4′ pieces at the store (or have them cut 1/16″ less than 2′ width to compensate for saw blade thickness)
  • Carpenter’s Glue – 1 bottle
  • Fabric to wrap around the panel (minimum 56″ width) – 8 yards
  • Spray Adhesive (optional) – 1 can
  • Staples (3/8″ or 5/16″ or so) – 1 package
  • Screws (wood, #10 x 1-1/2″) – 1 pack of 100
  • Finishing nails (1″ or so) – 1 pack
  • If you have a nailer, replace the screws and finishing nails with 1 package of brad nails (1″)
  • Hanging Hardware – Options include D Rings with Picture Hooks, Z-clips, or other picture hangers.

Sound Absorption Core Material

There are other options you can use for this. There’s a material known as Owens Corning 703, that has a history of use in many studios around the world. It is the name brand for this kind of thing. Over the years, many companies have developed similar products, and pricing has become far more competitive. The acoustical properties for the Roxul material is nearly identical to Owens Corning products, but at a low fraction of the cost. If Roxul Safe & Sound is not available at your local building supplies outlet, there are a few other options. Here’s a list of some materials, and their approximate pricing:

  • Roxul Safe’n’Sound – 3″ thick – $0.69/sqft
  • Roxul RHT 80 – 2″ thick – $1.24/sqft (may be able to find it for less)
  • Owens Corning 703 – 2″ thick – $2.13/sqft (difficult to find in Canada)
  • Johns Manville 817 – 2″ thick – $1.60/sqft (minimum)

Here’s a great site for comparing the sound absorption coefficients (the amount of sound absorbed at particular frequencies). You can see that these products have roughly the same effectiveness in absorbing sound over multiple frequencies. The Roxul Safe’n’Sound is definitely the best bang for your buck, and you can find it any Home Depot. Can’t go wrong! If you can’t get it as easily where you are located, you should be able to find one of the other options listed above.

Fabric

The higher end industry standard for this is Guilford and Maine acoustical fabrics. However, there are multiple potential fabrics to use for this application – but you can’t use just anything. It doesn’t need to be acoustically transparent, but it’s important to find a fabric that isn’t acoustically reflective. Absorptive fabrics (like felts) are okay.

The easiest (and generally least expensive) to use is burlap or jute, which both tend to have large enough holes between the threads to let the sound in, but not too large as to allow the fibers of the core material out. You can also use various cotton or polyester fabrics. Some say that if you can blow air through the fabric without too much resistance then you have a decent fabric for this application. You can use thicker fabrics, and they’re especially good for durability, but I’d just suggest not going for anything too thick unless it has thicker/textured threads (and thus appropriate spacing between them).

If you can take a good look at existing acoustical treatment somewhere, check the look and feel of the fabrics they use. If not, just use your better judgement. Be sure to get fabric that’s off a bolt at least 56″ wide (and preferably a little larger), so that you can wrap that around the 48″ length of your panel. Anything smaller and you’ll have to buy twice as much fabric!

(Commercial applications require panels that are up to fire code. Failing that, you may have problems with insurance. If you’re putting panels in a commercial location, do a little research on that before hand, and be sure you get appropriate fabric for that application.) Okay then, let’s get down to it!

Step 1: Prepare Your Materials

Use your miter or circular saw to cut the framing lumber to the right sizes (or have it cut where you purchased it). I’m going to assume you’re using the Roxul Safe’n’Sound, which is actually 47″ x 23″, so I’ll give cuts that suite that size. You’ll want the outside of the frame to be exactly 2’x4′. With the thickness of the frame at 3/4″, that’ll put the inside of the frame at 22.5″ x 46.5″. Don’t worry, the Roxul will squish quite nicely into the frame for a snug fit.

The edges of your frame will connect in a butt joint. Cut 16 pieces at exactly 24″, and another 16 pieces at 46.5″. When you account for the thickness of your saw blade, you won’t be able to get four short pieces out of your 8′ piece, so alternate. You’ll get two full panels worth out of every three 8′ pieces. Smell the pieces of lumber. Doesn’t freshly cut pine smell awesome!?!

Cut your fabric into 1 yard pieces. If you purchased exactly 8 yards, you may want to cut at 34″ instead of 1 yard to compensate for less than perfect cuts. 34″ will be more than enough. Your plywood should already be cut to 2’x4′ pieces before you leave your builder’s supplies outlet.

Recap

  1. Take your framing lumber and cut 16 pieces at exactly 24″, and another 16 pieces at 46.5″.
  2. Smell the freshly cut lumber (because it smells awesome).
  3. Cut your fabric at 34″ (assuming it’s from a 56″ or larger bolt of fabric). 8 pieces.
  4. Have your plywood cut at the builder’s supplies outlet into 2’x4′ pieces. 8 pieces.

Step 2: Build Your Frame

Line up the wood for your first frame. If you do not have a brad nailer, pre-drill a hole for 1 screw at each joint. Pre-drilling is crucial to keep everything aligned and prevent splitting. Apply the glue and screw the frame together. Keep in mind, the screw is only there to hold the frame together until the glue dries. The glue will form a much tighter bond than a screw could.

Apply a bead of glue all the way around the face of the frame and put a plywood backing on it. You may have to shimmy the frame a little if it’s a bit of a rhomboid. It probably won’t be perfectly rectangular until you adjust it. Now drive some nails through the ply into the frame. Don’t skimp on the nails.

Recap

  1. Line the pieces for the frame up in preparation for assembly.
  2. Pre-drill a hole for one screw at each corner (going through the 24″ piece into the end of the 46.5″ piece).
  3. Apply glue to the ends and screw each corner together.
  4. Put a bead of glue all the way around the part of the frame facing up.
  5. Put the plywood backing onto the frame and use it’s shape to straighten the shape of the frame.
  6. Nail the backing into place.

Step 3: Wrap The Frame In Fabric

Insert the core material into the frame. If you purchased spray adhesive, coat the center of the inside of the back panel with some adhesive first, and the edges of the core material if you desire. Put on some gloves before handling the core material. Roxul is a rockwool, which is essentially fiberglass. It’s not a health hazard, but it’s definitely an irritant. Wear long sleeves too, and wash you hands with cold water afterwards. Cold water keeps your pores closed while you remove any fibers that may be on your skin.

Once the Roxul is in the frame, set it aside and lay a piece of fabric down on your work surface. Place the frame face down onto the fabric, leaving even amounts of fabric on each side. The best way to wrap a panel is like how you wrap canvas for a painting. To ensure it’s tight and even, start from the center of each side and work your way to the corners, pulling tighter as you get closer to the corner. Staple the fabric down at the back. Don’t skimp on the staples. Every 3 inches or so should do the trick.

Recap

  1. Put on gloves before handling rockwool core material.
  2. Apply spray adhesive to the center of the inside of the back panel, and to the edges of the core material.
  3. Put core material into frame and set aside.
  4. Lay out a cut piece of fabric (34″ x 56″+).
  5. Place the frame with core material face down in the center of the fabric.
  6. Wrap the fabric around one of the long sides first. Start by stapling it into the plywood in the center of that side.
  7. Stretch the fabric from the stapled center toward one of the corners on that side (so that it is being stretched lengthwise on that side) and staple the stretched fabric every few inches. Do the same again from the center to the other corner on that side of the panel.
  8. Then do the opposite side, starting with the center, and this time making sure you pull the fabric tight across the width of the panel. As you stretch the fabric toward the corners, make sure you are stretching both length and width.
  9. Do the same process with the short sides, taking care to fold the corners neatly.

Step 4: Choose Placement

For placement, there are numerous techniques and every room and application is different. For the best and simplest rule of thumb in a home theater or control room environment, you’ll get great results placing them at first reflection points from your sound source. There’s an easy way to determine these spots.

  1. Sit in the seat you’ll normally listen from, facing as you usually would.
  2. Have a friend place a mirror flat against the wall and slide it around until you can see one of your speakers from your seat without shifting yourself to see try to see it.
  3. Mark that point with a piece of tape.
  4. Do the same for each speaker and each wall and the ceiling.
  5. Place your panels over as many or these spots as possible.

Step 5: Hang Your Panels

Mount your panels using the mounting hardware. Make sure you mount them safely. They’re not too heavy, but you certainly wouldn’t want one falling on you. If you are mounting to the ceiling, be sure to attach appropriate mounting hardware to the sturdier wood of the frame of the panel, instead of just into the plywood backing.

Instead of hanging the panels, another option for studio environments is to attach two panels together with hinges and use them as portable baffles for isolating amplifiers and drums.

Full Recap

If you haven’t watched the video tutorial yet, do that now! Okay, let’s do a full written recap:

Prepare You Materials

  1. Take your framing lumber and cut 16 pieces at exactly 24″, and another 16 pieces at 46.5″.
  2. Smell the freshly cut lumber (because it smells awesome).
  3. Cut your fabric at 34″ (assuming it’s from a 56″ or larger bolt of fabric). 8 pieces.
  4. Have your plywood cut at the builder’s supplies outlet into 2’x4′ pieces. 8 pieces.

Build Your Frame

  1. Line the pieces for the frame up in preparation for assembly.
  2. Pre-drill a hole for one screw at each corner (going through the 24″ piece into the end of the 46.5″ piece).
  3. Apply glue to the ends and screw each corner together.
  4. Put a bead of glue all the way around the part of the frame facing up.
  5. Put the plywood backing onto the frame and use its shape to straighten the shape of the frame.
  6. Nail the backing into place.

Wrap The Frame In Fabric

  1. Put on gloves before handling rockwool core material.
  2. Apply spray adhesive to the center of the inside of the back panel, and to the edges of the core material.
  3. Put core material into frame and set aside.
  4. Lay out a cut piece of fabric (34″ x 56″+).
  5. Place the frame with core material face down in the center of the fabric.
  6. Wrap the fabric around one of the long sides first. Start by stapling it into the plywood in the center of that side.
  7. Stretch the fabric from the stapled center toward one of the corners on that side (so that it is being stretched lengthwise on that side) and staple the stretched fabric every few inches. Do the same again from the center to the other corner on that side of the panel.
  8. Then do the opposite side, starting with the center, and this time making sure you pull the fabric tight across the width of the panel. As you stretch the fabric toward the corners, make sure you are stretching both length and width.
  9. Do the same process with the short sides, taking care to fold the corners neatly.

Choose Placement

  1. Sit in the seat you’ll normally listen from, facing as you usually would.
  2. Have a friend place a mirror flat against the wall and slide it around until you can see one of your speakers from your seat without shifting yourself to see try to see it.
  3. Mark that point with a piece of tape.
  4. Do the same for each speaker and each wall and the ceiling.
  5. Place your panels over as many or these spots as possible.

Hang Your Panels

  1. Hang on the wall or ceiling, being sure to use appropriate hanging hardware for their weight.
  2. If hanging on the ceiling, attach the hanging hardware through the plywood backing and into the actual framing lumber, instead of just the ply backing, which will be less stable on its own.
  3. Instead of hanging the panels, another option for studio environments is to attach two panels together with hinges and use them as portable baffles for isolating amplifiers and drums.

Aaaaaaaaand you’re done!!

Now listen to the results! If you’ve never experienced something like this before, you’ll be surprised at the difference between the sound quality of your room before and after this acoustical treatment. Your favorite audio, whether music or movies, will now sound as it was intended to (i.e. frackin’ awesome!).

I hope you enjoyed this tutorial! Check out our Facebook and Google+ pages, and subscribe to our mailing list to see future Weekly Creations as soon as they’re posted. And keep creative!

46 thoughts on “Week 16: Tutorial – How To Make Sound Absorption Acoustical Panels

  1. I’m kind of a noob when it comes to wood working … is a 1×3 exactly 1 inch by 3 inches? I heard somewhere that the actual dimensions are a bit smaller. If thats the case would i have use a 2×4 instead? Thanks in advance!

    • You are correct, a 1×3 is generally actually 0.75×2.5. a 2×4 will be a bit heavy, and thicker than necessary. You can get a 1×4 or use larger planks and rip them down to exact size on a table saw. Or you can stick with a 1×3 and just let it be a little cushiony, which actually looks pretty good with some fabrics!

      • Ok perfect. I will then use the 1×3 since they seem to work pretty well in your video. Thank you for the reply!

  2. great tutorial … thanks
    any idea if there is a fabric with a similar look to artist canvas that i could paint on to make them look like real art?

    • Hello Colleen! Well actual canvas is definitely too thick and too tight of a weave for acoustic purposes. If you get bleached burlap or jute it should work half decently, though I’d imagine the rough, uneven surface would be hard to work with. A breathable cotton/polyester blend might be a good second choice if you can’t stand painting on something as awkward as the burlap, I just worry that the paint would reflect all the sound if the fabric has too fine threads or too tight of a weave. You don’t want to fill the holes, so I’d suspect you wouldn’t want to use gesso or oils either because they’ll be too thick for the sound to get through to the absorption material. I think you’d have to use a fairly watered down acrylic

      Another option is to get prints of your work done by a place that prints on fabrics. Certainly not the money saving route, and maybe not as fun, but they’d look great and sound awesome if you had them use a fairly breathable fabric. I think that will be one of the next few options I add to the panels I make professionally.

      Please do let me know what you try and how it goes!

  3. Hiya Mike,
    Love what you did here.
    Had a question.. I’m concerned about plywood causing cancer if you’re around it too much, I have a bedroom/studio and want to build these panels for it but am not %100 sure.. what do you think ?

    • Hi Paul! I’ve read a little about the use of formaldehyde in the resins of pressed wood products. Fumes that come off of products with high uses of formaldehyde could potentially be a carcinogen after many years of exposure. However, in North America this isn’t generally a problem because we have stricter manufacturing standards for this type of thing. In fact On July 7, 2010, President Obama signed the Formaldehyde Standards for Composite Wood Products Act addressing this very topic. Though from what I understand, safe levels have been common practice in North America long before this was signed to make it mandatory for all manufacturers..

      MDF has the greatest use of these resins, and it’s especially advisable that you wear a mask while cutting any pressed wood to avoid breathing in the resin-contaminated saw dust. Though most finished products in your house will not be something to worry about. Keep in mind that most kitchen cabinets and the vast majority of Ikea-type furniture are also pressed wood of one type or another, and of course these things rarely cause any problems.

      That said, if you live outside of North America, you may want to check out the particular manufacturing process of the plywood available in your area and regardless of where you live, exterior-grade plywood supposedly uses a lower-emitting resin.

      Here’s an article by the Environmental Protection Agency that may or may not help you decide what’s best for you. http://www.epa.gov/iaq/formaldehyde.html

      Hope that helps!

      • In fact the plywood is detrimental to function of the panel. Sound waves should pass through the rock wool panel, hit the wall then travel back through the Rockwool again. Ideally there should be a 1/2” between the panel and the wall.

        • Hello! There’s a bit of a common misconception there. An air gap is indeed beneficial, but not as beneficial as simply using thicker Rockwool. For example, 1″ of Rockwool with a 1″ gap is not quite as good as just 2″ of Rockwool, and 2″ of Rockwool with a 1″ gap is not quite as good as simply using 3″ of Rockwool. At best the assumption is that the air gap is just less expensive because it requires less material, though even that proves misleading because the fabric you’ll need to seal the back is generally more expensive than the backing ply, and then you’ll still have to add additional framing supports for the structural integrity of the panel.

          There’s no difference between the sound waves bouncing off the drywall then going back through the Rockwool and the sound waves bouncing off a backing ply then going back through the Rockwool.

          The two key factors in the absorption potential of a panel are 1) the distance between the front of the Rockwool and the solid object behind it (whether drywall or backing ply) that will reflect the sound back through the panel, and 2) the amount of absorption material within that distance. So yes, adding an air gap to a soft back (fabric back) panel will indeed extend the range of absorption to slightly lower frequencies, but so would adding another inch of Rockwool – and the Rockwool would do a better job.

          So you could indeed put a soft back on a wall panel and offset it by an inch or so. Or you could just use a thicker Rockwool core. Our company (Inity Acoustics) makes both, and usually recommends the hard back for walls and the soft back for ceiling panels where lighter panels are desirable and the hanging hardware inherently creates an air gap that you may as well take advantage of.

          Soft back panels are also great for straddling a corner when bass traps aren’t an option for whatever reason. Of course – as with the walls – using full corner bass traps where the entire cavity behind the face of the panel is filled with Rockwool is far more effective than a thinner Rockwool face with just air behind it..

  4. Great tutorial! I’m pretty sure I’m going to go this route so thank you for the detail.

    Wondering if you can comment from your experience, if these in sufficient quantity/arrangement would help with reducing the noise perceived outside of the space. Eventually I will have door gaskets, no windows and accoustical sealant around all the cracks I can find in my budget attempt to get nearly airtight. The walls and ceiling are built though and I can’t do much about it so I’m leaning towards panels, and putting a layer of Safe n Sound on top of my drop ceiling tiles. I know I won’t get soundproof but I want to seriously dampen the sound my drums emit to anyone outside the room. Luckily one wall and the floor is cement (carpeted).

    Regarding fabric, can you suggest product (quality but cost effective) and a retailer in Canada that you’d personally use? I’m in Saskatoon so shopping isn’t that great but we have some variety. Or is it simpler than that, just hit up Fabricland and go?

    Thanks again.

  5. Hi Mason!

    I’ve seen decibel tests from just outside a room before and after sound absorption sheets (which are less effective than the Roxul panels) were placed on the walls and there was a roughly 20 dB reduction in sound.

    But yeah, if you really want to get that decibel level down, making the room airtight and adding some isolation treatment will be a big help. You’re on the right track for sure with adding the acoustic sealant and Roxul above the ceiling tiles. Be sure to seal any wire holes and the such while the drop ceiling is down.

    If you really want to avoid opening the walls to add Roxul, but are looking to do a little more than what you have already planned, you could also get some Green Glue and extra drywall. You literally just apply this stuff to a fresh sheet of drywall and slap it on top of the existing wall. It’s touted as a phenomenal product, and should work fairly well on your non-cement walls, even if it would be better with the Roxul in the wall as well.

    But yeah, if you’re keeping the budget manageable I think you’re on the right track with your plans right now.

    As for fabric, I’d avoid Fabricland. I find them too pricey for this kind of thing. Look for a smaller retailer with maybe just a store or two in your area. Burlap is the easiest choice, but a good selection of colors and a good fabric weight (11oz for burlap is good) is hard to find in Canada, even here in Toronto. If you want something a little nicer than your local burlap selection, make sure the sound can get through whatever fabric you’re looking at to be absorbed by the Roxul. With many fabrics it can be a balance between something thin enough for the sound to get through, but thick enough that you won’t see the frame. As such, darker colors tend to look better.

    Fabric choice is probably the single hardest part of making these panels, but you should be fine if you just don’t go too thick or too thin. But that said, if you’re having trouble finding something suitable locally I could probably put together some of the fabric I usually use and ship it to ya. The red fabric used in the video is from Portugal and is a cotton/wool blend. I get it in brown, beige, red, sky blue and dark blue. I also get a cotton/polyester fabric for black and a couple other random colors. I haven’t put much thought into reselling it before, but if you need some and can’t find good local fabrics at a suitable price I suppose I could pass some along for $9/yard (56″ width). Each 4’x2′ needs about 1 yard. I haven’t a clue what the shipping would be.

    Either way, please check back to let me know how it goes! I’d love to hear about your results. 🙂

    • Thanks a lot for the reply!

      I’m a bit worried about how difficult getting the Roxul on top of my ceiling is going to be but I’ll work through it somehow. I’m envisioning starting at the edge, gradually removing tiles to work and then replacing them to put the stuff on top.. the wires and crap will hopefully not fight too much.

      I wish I could afford Green Glue it looks awesome, but according to my math I’d need about 1.25 buckets worth to do all my walls which is pretty much the entire budget, but still need ceiling, doors, drywall..

      Very generous to offer to ship some cloth, but I probably can’t afford it! I found this stuff which is super cheap http://hometex.ca/fabric/burlap/burlap-rolls. I may dye it darker.

      Do you think it’s unwise for me to aim for 2×6 panels instead? I’m thinking about making a few to see how much they reduce the noise transmission and go from there, maybe just putting them all over the room.

      I should be starting construction this week so I’ll let you know how it goes 🙂

      • If you have lights in the ceiling, I’d personally consider swapping them for wall lights or lamps to be able to just do the whole ceiling. Consider it if it’s an option.

        The burlap link looks good. Please do let me know how the material looks and feels if you get it. Burlap tends to not have the problem of seeing the frame with the lighter colors – at least not as much – so you should be fine with that color if you like it.

        2’x6′ panels work great hinged together to sit on the floor like an open book. And hinges are less costly than most hanging hardware too. They’re just a bit more work to make them look good because you’ll probably want to put a layer of fabric over the back panel and staple it in a visually pleasing manner. If you’re planning to do that, cut 80″ off the 60″ roll and then cut the 60″ into 34″ for the front and 26″ for the back. But if you’re placing them so the back will never be seen, I’d recommend grabbing a 72″ roll so you can get two front pieces out of your 80″ cut.

        Here’s some examples of the ones I make: http://toronto.kijiji.ca/c-PostersOtherAds-W0QQUserIdZ19496476

        I’m looking forward to hearing back from you about how it goes!

  6. Hello,
    I am considering making these for my piano room in my house instead of buying. I have a lot of windows in that room, so I do not have a lot of wall space to hang the panels. I want to use the stand-alone hinge idea, but four feet tall is not going to cut it since I want to be able to put it in the open doorway (open concept house is not the ideal way to achieve a quieter house!). I want to use it a buffer for the rest of the house but also a privacy fence when I need my space from tiny hands (my wonderful children). Do you suggest I just measure the doorway height and keep the 2′ width? or change the width as well? Also if I use burlap, I would like to get some sort of artsy or musical picture printed on it, do you have an recommendations on how to go about that?

    Thanks for the video. I feel empowered.

    • Geez! So sorry I missed your comment here!

      I’m glad you feel empowered! Yeah, you can definitely make the panels bigger. But I’d stick with something that works well when cutting down from the standard material sizes of 8′ lengths for the frame, 4’x8′ sheets for the back panels and 2’x4′ Roxul inserts. I now regularly make a 6’x2′ panel with one and a half Roxul pieces in it and hinge two of them together. With a few of them you can even make full vocal booths with a roof and all that way. Works beautifully!

      Here’s a link to get a better idea: http://toronto.kijiji.ca/c-PostersOtherAds-W0QQUserIdZ19496476

      You could go bigger as well, if it better suits your space, but I like 6’x2′, all things considered.

      As for printing, I’ve yet to sort out a solution to that. If you find something that works, even if expensive, please do come back to comment what you’ve come up with!

  7. Mike: I’m tasked to do sound treatment for a local high school’s dance studio. The room is 65x45x22′ tall and it is very “live”. On the long sides, there are windows from 8′ up to about 18′ and we’ll have to swap out the rather reflective window treatments to get any help on those surfaces. As to the end walls, one end has 8′ tall cabinets and the other end has various doors and the like. So how much spacing should there be between panels? On the studio pic above it looks like 4″-8″ behind the drums. We’ll also probably have to double or triple stack panels to get full coverage. Thanks for the tip in fire retardant fabric.

    Dan

    P.S. We might encourage the dancers to decorate the panels with felt cutouts etc.

  8. Hi Michael,

    Excellent presentation!! …thanks for sharing your expertise derived from your experience. I’m helping a friend try and solve his acoustics problem in his church
    fellowship hall. I had good success at our church using wedge foam glued to 4X8 fluted coraplast panels, but didn’t know about Ruxol at the time and think it’s the way to go on this project. How do you mount yours to the walls? Also, have you tried 1/8″ pegboard as a backer?….seems like it would be more effective due to it’s perforations. Thanks! – Frank from Western KY, USA.

    • Hi Frank!

      Yeah, if you plan to offset the panels with an air gap behind them then you can use pegboard backings and it works well for allowing bass frequencies through to take advantage of the airspace and effectively extend the absorption range. Now of course an extra inch of airspace isn’t as effective as an extra inch of Roxul, and you’d also require fabric at the back to hold the Roxul fibres in. Also, fabric backings without the pegboard will do mostly the same thing but weigh less, so I’d only recommend the pegboard (or other slotted wood) method in special circumstances, like when trying to create frequency crossovers for the effect of allowing the bass frequencies through to be absorbed, while reflecting a lot of the treble, to keep the room “bright”. In this case the slotted wood or pegboard is more practical on the face of the panel (or close to it), and this is more particular to high fidelity listening rooms or studio applications. It’s less relevant or desirable in general purpose applications like rehearsal rooms, offices or public spaces that just need the echo tamed for improved audio clarity.

      That said, there are a few instances where I’d recommend soft (fabric) back over a thicker hardback panel; generally any time that you’d prefer the panel be lightweight, or any time the panel will be hung in a way that will create an air gap regardless, like ceiling panels. With a large space like a church hall you’ll usually want 4×8 panels, so I’d go with soft back. With soft back you’d just want to put some mitered corners inside the frame to keep things squared up to 90 degrees, and then also a brace inside the center at the back for larger panels. Then, either cut the Roxul to accommodate the corner or have your frame a little thicker so the Roxul can sit on top of the mitered corners and back brace, leaving the back of the panel slightly inset. Put a cheap fabric in the back first and then the Roxul, then wrap the nicer fabric front.

      Your end result will look something like this at the back of the panel: http://marccarlton.com/wp-content/uploads/2011/08/Back-Side-Stapled-31.jpg

      You have a couple options for the hanging hardware with this approach. If you made the frame thicker to accommodate the corners and brace, then you could use the little inset on the back to put in picture hanging wire like in that photo. For ceiling panels or panels without the thicker frame you can put eye screws into each corner at the back, which you’ll attach to some hooks going into drywall plugs in the wall/ceiling.

      Hope that helps! Best of luck!!

      • Thanks, Michael…I sincerely appreciate your very thorough response and I believe you’ve helped enormously in our decision making. In order to avoid
        the framing I’m inclined to run horizontal 2″X4″ stringers parallel to the floor,
        24″ o.c., then mount 1″ of Ruxol (NRC 0.45) between the stringers, and cover the Ruxol with a 2′ X 4′ laminate panel of 1/8″pegboard w/ 1″ wedge
        foam(NRC 0.40) glued to the front side. With 15% perforated area on the PB.
        I figure the NRC should be 1.0 in total. Does that make sense? Thanks! FE.

  9. hey i live in india and dont have access to the material required for soundproofing, so can i instead use sheets of fibreglass as the absorbing material ?

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  11. Hi. Thank you for your helpful information. I was told I could make sound panels for my classroom because I have trouble hearing with extra noise, like trying to hear one student with other students’ voices bouncing off the walls. My audiologist said in her office they stapled felt around canvas frames and just hung them on the walls. I could not find just the frames, so I stapled felt over frames with canvas on them already, just layered the felt over the canvas. The canvas has primer on it. Will this defeat what I am trying to do? I read what you said above about canvas being too tight a weave for sound to go through…should I cut out the canvas or will they be ok since the felt is over it? Thank you.
    Susan

  12. Thanks for this Mike – brilliantly detailed tutorial and I’m very excited to build my own 2X6 panels here in Winnipeg this week if I can source all the necessary materials locally.

    Any chance of a tut on how you construct your bass traps? I’m curious how you cut and position the rockwool to create the triangle shape.

    Cheers,
    James

  13. I want to build panels to put on a massage room wall to cut down on noise will these work for that purpose as well?

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  15. if im building a 5 wide 6 long 8 tall vocal booth…. in theory i could put the roxul between the studs and just cover the inside with fabric and ply-wood the exterior…
    correct?

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  18. Great tutorial here. I’m in the process of building some acoustic panels and moving away from Fiberglass. I’ve never delt with Roxul before, it seems to be more forgiving as it’s squishy.

    Here are my questions, please understand, I’m not trying to be difficult, I just want to make sure I understand your directions

    //Your Words//
    “Use your miter or circular saw to cut the framing lumber to the right sizes (or have it cut where you purchased it). I’m going to assume you’re using the Roxul Safe’n’Sound, which is actually 47″ x 23″, so I’ll give cuts that suite that size. You’ll want the outside of the frame to be exactly 2’x4′. With the thickness of the frame at 3/4″, that’ll put the inside of the frame at 22.5″ x 46.5″. Don’t worry, the Roxul will squish quite nicely into the frame for a snug fit.”

    So what you’re saying here is for each panel, there is a 24 inch piece and a 48 inch piece. the The inside of the frame will be 22.5 and 46.5

    Now, I’ve already made a cutting mistake as didn’t compensate for the size of the blade. Half of my cuts (for full frames) are 24 inch x 48inch meeting the inside measurements you’ve listed above.

    My other half of the cuts are 47.75 – 47.875 inchs and 23.75 inches. This would be a much more snug of a fit as my measurements are off. Would this be acceptable or shall I scape the woold and make then exactly 24 inch x48inch.

    “The edges of your frame will connect in a butt joint. Cut 16 pieces at exactly 24″, and another 16 pieces at 46.5″. When you account for the thickness of your saw blade, you won’t be able to get four short pieces out of your 8′ piece, so alternate. You’ll get two full panels worth out of every three 8′ pieces. Smell the pieces of lumber. Doesn’t freshly cut pine smell awesome!?!”

    Here’s the confusion. Above you said the cuts needed to be 24in x 48in so that the inside was 22.5×46.5, but here you’re saying 24″x46.5″ those making the inside of the frame much smaller.

    Was this a typo? Also in your video you mention the cuts need to be 24 inch by 46.5

    Please let me know, thanks again

    • I didn’t say the cuts have to be 24in x 48in. I said that the outside of the frame will be that size. With butt joints, the sides of the frame will be inside of the top and bottom.

      Because the frame boards are 3/4″ thick, you have to compensate for that thickness when cutting the sides that will butt up against the top/bottom. So if you cut the sides at 46.5 and place a top and bottom on them, the inside of the frame will still be 46.5 (it just has a “lid” on it), but the outside will be 1.5″ longer (3/4″ from the top board, 3/4″ from the bottom), which is 48″.

      Consider this image: http://fscomps.fotosearch.com/compc/ULY/ULY285/u98502728.jpg

      If the sides were 48″, then the outside of the whole frame would be bigger because of the top and bottom.

      I hope that’s more clear.

  19. Hi Mike, thanks for the tutorial. I have a slightly different problem – echo in a high cathedral ceiling. I don’t want to put panels on the ceiling, but I have very tall cabinets with room at the top to place panels horizontally on top of the cabinets. My room is very large – say 500 square feet and a 25 foot ceiling (45 degrees). I have room for about 30 feet of panels by 2 feet, so about 60 square feet for panels – do you think it would make a difference?

    • Everything will make a difference, though it would certainly be more effective to treat the ceiling, or a little more wall space if possible. But yes, if you’re stuck with that plan, you will still make a difference. I actually treated a hall in a church in a similar way a little while back and it made a significant difference in making the room bearable with a bunch of people speaking to each other in it.

      Seeing your room would allow me to be more specific. Let me know if you want me to connect over email so you can send a pic.

      Cheers!

  20. Mike, thanks for your response – I tried just putting the bats up temporarily above the cabinets – it did make a difference – not night and day, but an improvement. I will complete the process and frame them and cover them so no material escapes. One more question – have you ever installed a panel underneath a long table? We have a very long dinning table and could squeeze a couple bats under there. We are going to add curtains and a few more area rugs as well to help cut down the echo. Let me know your thoughts on the table.

    Regards

    • Hi, Neil!

      Once upon a time you could find some cheap materials to make a panel for as little as $20. You’ll likely spend more than that now, even with inexpensive lumber and fabric, but I bet you could still build something nice for about $30.

  21. Hi Mike!
    Thank you for this tutorial, I’ve been following it and just finished my first panel (I didn’t do the best job, but it works).

    Would you say nailing the back sheet to the frame is a necessary step? I’m only asking because I don’t have a workshop or a nailer or anything so I’m doing all of this at home, and hammering nails is really really loud.

    Thanks!
    Leo

  22. Hello Mike,

    I have currently made 5 acoustic absorption panels that are sized at 30 inches wide and 71 inches tall. I have made a vocal booth with these with one of the panels ontop for ceiling cover. Does this technique work well would you say? It has been a great improvement so far. Much clearer and crisper sound. Would you recommend making a full vocal booth all the way around myself, or is it ok just having the back, sides, and top covered as I already have a portable booth enclosure on my mic stand for the back of the mic. Any input you have on this would be greatly appreciated! Look forward to your response! CHEERS,

    Brad

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