How I built my bass traps...

[Gharper23]

I just finished my traps tonight and put them in place and WOW. the room sounds sooo much better. It's amazing really. Best $300 I ever spent. Thank you everyone for the help.

[questionable]

Yep, the change in my room is very noticeable. I don't have the capability to test right now, but will when I get a chance. However, I could hear problems in my room on normal recordings before, and now those problems are pretty much gone. I know I still have some room for tweaking, but I'd guess I'm already 75% of the way there.

[Pretension]

For all of you that are reading this forum and wondering whether to build your own acoustic treatment whether it be bass traps or otherwise you should check out this video that I made.



Hopefully you should be able to hear the difference that it has made to my studio. Enjoy!

[Gharper23]

cool video, I just did 10 Diy basstraps and my room sounds 100% better.

[cooker]

Originally Posted by Pretension

For all of you that are reading this forum and wondering whether to build your own acoustic treatment whether it be bass traps or otherwise you should check out this video that I made.



Hopefully you should be able to hear the difference that it has made to my studio. Enjoy!

Very nice, difference is night and day (or with-without the non-existing reverb )

[Pretension]

Originally Posted by Gharper23

cool video, I just did 10 Diy basstraps and my room sounds 100% better.

Yeah it's good to hear it hey. It's amazing what a couple hundred dollars and a few hours can do.

Glad you guys liked the vid.

[HDJK]

Originally Posted by dykstraster@gmai

...

Odds and Ends

Frames are purely for looks and mounting...they aren't even really necessary, and in fact, the less of your absorption you have touching a wooden or metal frame, the better it preforms.
...

I have a question regarding this:

I'm about to build a riser for the sofa (my home studio also functions as a listening room plus home cinema) with 3 Europaletten plus frames.

I was going to fill them with Rockwool so they can act as bass traps. Will this have any effect at all? I wanted to stuff them full to avoid any resonance of the 3 wooden boxes, but since you wrote touching the wooden or metal frame reduces the performance, is this a bad idea?

Thanks for the info.

[dragonxking]

Originally Posted by Pretension

For all of you that are reading this forum and wondering whether to build your own acoustic treatment whether it be bass traps or otherwise you should check out this video that I made.

Hopefully you should be able to hear the difference that it has made to my studio. Enjoy!

excellent video! thanks for taking the time to share your experiment with us. i absolutely love the color scheme of your studio with the bass traps and everything. looks great man

[bpape]

For some reason I can't get that link to load for the product you're going to use for the riser. In any case, there are a couple of things to consider.

If the riser is fully enclosed, it will need to be filled with insulation to prevent ringing. The top can't act as a panel absorber because it will be damped by the furniture. The sides might do a little something but you don't know what due to it likely being relatively short and stiff.

Now, if you use something where the sides are open and the top is solid, then absolutely, it will act as a broadband absorber - still needs the insulation.

Bryan

[Arksun]

Originally Posted by bpape

Now, if you use something where the sides are open and the top is solid, then absolutely, it will act as a broadband absorber - still needs the insulation.

Bryan

For a shorter tri-corner based trap that would go under a desk, would it be beneficial to make the top and bottom triangles (or squares if its shaped that way) open framed instead of solid top and bottom pieces?

[phillis]

guys this is by far the best thread on this forum. im so inspired to get stuff done now!

Few questions though:

ive seen the term '703' come up a bit. is that a density? i live in australia so everything avalible here is totally different to american/europe. whats something specific i should look for in the insulation im buying?

whats the best way to mount these on the wall but so they dont sit flat on the wall? id like to make 6 or 7 of these, one of them a cloud- should i treat the cloud/cieling panel any differently?

to use these as bass traps, should they be the entire height of the room?

and the last one, im a bit confused as to how these should be mounted in corners as bass traps, there was a bit of arguing about weather they should be air tight or what...whats with that?

thanks heaps guys!

[waveheavy]

It'd also be nice to find an Acoustisorb (made in Australia) dealer in the USA. Appears to be a very nice alternative to OC 703 or mineral wool.

Pretension,

Most excellent video you made. Production was amazing too!

[Pretension]

Thanks for the comments waveheavy and dragonxking. I appreciate it.

As for the Tontine acoustisorb in the states, I am not sure if it's available there but I am sure that someone would be creating a similar product. This is the spec sheet (http://www.soundblock.com.au/pdf/ton...ustisorb_3.pdf) for those of you that may want to track down a similar product over there.

It's easy to work with, reasonably priced and works just as well.

[phillis]

Originally Posted by Pretension

Thanks for the comments waveheavy and dragonxking. I appreciate it.

As for the Tontine acoustisorb in the states, I am not sure if it's available there but I am sure that someone would be creating a similar product. This is the spec sheet (http://www.soundblock.com.au/pdf/ton...ustisorb_3.pdf) for those of you that may want to track down a similar product over there.

It's easy to work with, reasonably priced and works just as well.

Hey pretension- ive been following your blog for a while. I like it, and your panels. awsome stuff. as a fellow aussie, id like to know where you got that stuff from- bunnings? or is it a bit more of a hassle to get your hands on them?

And to everyone else, ive just managed to get 40 of these at a good price:



they measure 12" (300mm) square. What would be a good way to arrange these to have the same or a similar benefit as the panels everyone here is making?

[PaulP]

Originally Posted by Pretension

As for the Tontine acoustisorb in the states, I am not sure if it's available there but I am sure that someone would be creating a similar product. This is the spec sheet (http://www.soundblock.com.au/pdf/ton...ustisorb_3.pdf) for those of you that may want to track down a similar product over there.

It's easy to work with, reasonably priced and works just as well.

I've just gone through a search for this stuff and every single link I came
across was from Australia. Why would this be ? I smell a conspiracy

Seems to me polyester would be ideal, though probably more expensive than
mineral wool or fiberglass.

Paul P

[Pretension]

Originally Posted by phillis

Hey pretension- ive been following your blog for a while. I like it, and your panels. awsome stuff. as a fellow aussie, id like to know where you got that stuff from- bunnings? or is it a bit more of a hassle to get your hands on them?

I'm in Brisbane, and I got mine from a place called Plastamasta. There's a few stores around town. I've also heard of it being available at some Bunnings but they didn't have it at my local.

If you are elsewhere in Australia I'd suggest calling around various insulation suppliers. I managed to find out about Plastamasta via another forum so you might need to do a bit of investigating.

and PaulP..... we've been stockpiling the stuff for years. We use it to line our bomb shelters such that when the invasion from the northern hemisphere comes, we can all hide away and have super loud rave parties underground. haha. Do you want me to put you on the doorlist?

[jimmieee]

Originally Posted by briansmallroom

I completed my own first round of traps and absorbers today (7 panels in total). They came out to just about $22 per trap. I used 1" Certainteed 703 equivalent, black burlap from Joanne's for the front, thin weed control fabric for the back.

Hey man, can you post some pics of your stands? They look gr8!

[MrCrowbar]

Originally Posted by mikedevelta

I Read the whole thread from front to back, love this trap design. I'm just wondering how you would mount those a few inches off the walls? There's not much frame to drill into and the good places already have screws in them. All I see on those pictures is a hole in the middle of the short side of the frame.

[Adlen]

For obvious reasons (27 pages) I haven't read every post here but I was wondering something...

I'm planning to build my traps soon as I have a load of Rockwool left over from a thermal insulation job. I was planning to use aluminum to build my frames. Thin U-channel stuff to cover the sides (and a small bit of the front and back) to ensure everything stays in place (they will be getting transported between my two locations every so often) and a piece of hardboard on the back to staple my fabric to. Is there a problem with me doing this? Do I need to keep the back open? Also, do I have to take the foil off of the back? Is there a problem using metal instead of wood?

I never even considered these issues until about 5 minutes ago when I thought about air going THROUGH the traps, with hardboard on the back, how is it getting through. Will my design be better if I keep the hardboard to a minimum (lots of large holes)?

Thanks in advance thumbsup

[rockear]

Posting to say this thread has been a great resource and to say thanks to everyone who posted their designs. Special thanks to all the pros coming here to share their technical knowledge.

I wanted to share my design as well, as I haven't seen anyone doing it exactly this way. My main constraint was cost. I was able to put these together for about 25 bucks a piece. I wanted them to be a little more rugged, so I can move them around for location recording without damaging them. That's why I put the wood on the outside of the fabric. I was kind of wondering if anyone thinks this will have a detrimental effect on their absorption properties. I'm kind of committed to the design at this point anyway I guess.




The wood is 1x2 fir from Home Depot. It's garbage wood, but if you spend a little time sorting it, you can find some straight pieces. It's only 80 cents for 8 feet. I would have preferred to buy from a local lumberyard, but the guy at the pro desk was very helpful in helping me track down the OC 703, so I felt better about it.

The fabric is 1.50 a yard unbleached muslin from Jo-Ann fabric.

OC 703 from a local supplier.

[takman]

Originally Posted by Adlen

For obvious reasons (27 pages) I haven't read every post here but I was wondering something...

I'm planning to build my traps soon as I have a load of Rockwool left over from a thermal insulation job. I was planning to use aluminum to build my frames. Thin U-channel stuff to cover the sides (and a small bit of the front and back) to ensure everything stays in place (they will be getting transported between my two locations every so often) and a piece of hardboard on the back to staple my fabric to. Is there a problem with me doing this? Do I need to keep the back open? Also, do I have to take the foil off of the back? Is there a problem using metal instead of wood?

I never even considered these issues until about 5 minutes ago when I thought about air going THROUGH the traps, with hardboard on the back, how is it getting through. Will my design be better if I keep the hardboard to a minimum (lots of large holes)?

Thanks in advance thumbsup

you want as much insulation exposed as possible, so yes, def. want the back open...

if you have foil on the rockwool, it should be facing the front not the back. people use the foil so they dont make room too dead.

wood or metal is a matter of personal preferance, and ease of construction. I like wood better, easier to make the frame with IMO and gives you something to staple the fabric onto..

You can makes holes/design into the sides of the bass trap, makes them more efficient...whether it be metal or wood....

[takman]

Originally Posted by rockear

I was kind of wondering if anyone thinks this will have a detrimental effect on their absorption properties.

No. Wouldnt make a difference if it was covered with fabric...

if it did, you wouldnt be able to tell the difference anyways...

the sides of the frame are open...so they will work well.

[rockear]

Originally Posted by takman

No. Wouldnt make a difference if it was covered with fabric...

if it did, you wouldnt be able to tell the difference anyways...

the sides of the frame are open...so they will work well.

Thanks takman. That was my thought as well.

Compliments on your build by the way. I wish I could have made mine as attractive as yours. I had to do these with a hand saw! I keep telling myself "You can't hear how they look."

[takman]

Originally Posted by rockear

Thanks takman. That was my thought as well.

Compliments on your build by the way. I wish I could have made mine as attractive as yours. I had to do these with a hand saw! I keep telling myself "You can't hear how they look."

thanks.

yea no worries, they will get the job done.

[Millo 3.1]

Originally Posted by Ryuben

To cut them into triangles, cut your 2x4 sheet of wool in half so that you have 2 2x2 sheets. Then get a straight edge and a knife and cut those 2x2's in half *diagnally*
Then just stack the triangles on top of each other.

Attached is what I did with OC703 for my corner traps - I put them into a frame and covered them with GOM.

As a side note - I ended up elevating my corner traps so that I can make use of the electrical outlets that are in my corners...I know it would be good to get that floor/wall/wall corner...my studio is not in a permanent location so later, when I move my small studio, I can remove those legs and make these corner traps stackable in my new space.

EXCELLENT! I was thinking of doing something like this! I plan to stack two of each front corner of my room and cover the whole 8' height. Do you guys think this will work well? In terms of the absorptive material, can it be Safe N Sound, or should it really be OC703? I'm just kinda unsure because of the itchiness issues w/ fiberglass, didn't want to have to cut all that much. Also, do the wooden bars on the back affect anything acoustically? Was planning on using facing, glued to the front fabric.

Like Ryuben, I also want my superchunks to NOT be permanent.

[Arksun]

Originally Posted by Millo 3.1

EXCELLENT! I was thinking of doing something like this! I plan to stack two of each front corner of my room and cover the whole 8' height. Do you guys think this will work well? In terms of the absorptive material, can it be ULTRAtouch or Safe N Sound, or should it really be OC703? I'm just kinda unsure because of the itchiness issues w/ fiberglass, didn't want to have to cut all that much. Also, do the wooden bars on the back affect anything acoustically? Was planing on using facing, glued to the front fabric.

Like Ryuben, I also want my superchunks to NOT be permanent.

Ultratouch should be good at the 3.5" thickness, but dont go for anything thicker, as the absorption properties seem to indicate that it might start to reflect at greater thicknesses.

I myself decided to take a big gamble and buy some unproven Isonat hemp/cotton stuff. I knew the 100% hemp was good acoustically, but I couldn't find any in stock at thickness I wanted so went for half hemp half cotton. Still waiting for proper figures on the hemp/cotton mixture (specifically waiting for gas flow resistance values.)

The stuff was an absolute bitch to cut, tried saws, blads, scissors, nightmare. Easy to use with hands, no protective gloves needed. I have very sensitive skin, rashes easily and I didn't get anything from man handling this stuff.

I still decided to wear mask whilst cutting though just to be on safe side.

Initial testing of just single panel on back wall didn't show much change in problem bass frequencies, but it did seem to improve the general soundstage quite a bit. Instruments sounded a tad more clear and could slightly better identify their pan position. This was with insulation just sitting loosely in frame. Hopefully once fabric goes on it'll still be as effective.

Once I get the air flow resistance figure I'll have a better idea of whether to stick with 100mm thickness or go 200mm for the other panels...

P.S. The insulation absolutely STANK when I first got it. Almost like a vinegary smell, must be the kind of salt they use, ammonium salt maybe?. Gonna let it air for few more days before I move it permanently into the studio.

[Millo 3.1]

Originally Posted by arksun

ultratouch should be good at the 3.5" thickness, but dont go for anything thicker, as the absorption properties seem to indicate that it might start to reflect at greater thicknesses.

thanks for your reply!

[Arksun]

One interesting thing I noticed was. When I played some white noise out of one speaker and put my old 4" Auralex foam in front of it, the change in sound was a bit like someone putting a low pass filter on the noise at around 8K.

When I held some of the insulation in front of the speaker in same place, the sound was very similar to how it was without, just at a slightly quieter volume, which I'm guessing would indicate that its a much more even amount of absorption across most the frequency range.

Another good reason why insulation trumps foam treatment (unless your specific aim is to just roll off the higher frequencies of course).

[Lonely Raven]

I've been meaning to post some of these for a while now. Just some fun projects I have going on for my home theater.

Some super-chunks I made so I could move them if need be. But then, I have no other corners I could move them to, so they kinda just stuck in the corner they are in. Each is 34" wide by 4' tall, and stacked they wedge floor to ceiling.







Here is how they look in the theater.





Some broadband absorbers. These are JM 814 (OC703 analog) wrapped in Dazian Expo Cloth. There is no frame, so the corners aren't very sharp, but they look good unless you really come up close to inspect them.









Rear wall flutter breaking diffuser. I had some nasty slap echo front to back, especially since adding a 10" diagonal screen to my room. These helped break it up, and improved the surround sound slightly. The middle ones are 4" deep QRD from the Decware plans, but made larger since this is the material I had handy. The sides, are literally 20 year old stair treads that I dato'd slots in on my table saw. Everything was stained a warm cherry color, with no clear coat. Even the MDF came out great with a good oil based stain!










Some C.W.A.L bass traps from Decware.com I'm skeptical that these work well (or at all), but in my old apartment which was really small, they seemed to do something, though I have no measurements from that time. I've had these for about 10 years. They aren't pretty, but I still keep them around.





And finally, my "proof of concept" 2D QRD Omnifuser. I'm working on building up a Prime 29 version that will be about 30" X 30", I'll have photos of it at a later date.





I'm working on some 4" thick broadband absorbers, and some sort of cloud, plus the pair of Prim 29 Omnifusers over the next two weeks. I'll post them as I have them!

[maccare]

Originally Posted by macmod

Hey, is everyone off the Ethanian panel traps nowadays?
I've made a couple under the impression that they'd be more efficient basstraps than 'plain' rockwool in a frame ...

Best regards,
Macmod

yes, a good question that is .