How-to create DIY Tri-Traps

[GoVeganDude]

I realize this topic has been posted on quite a few times, but I think I need some clarification on DIY superchunks/corner traps/tri-traps. Money is somewhat of issue, I would love to keep material purchases below $300 for 4 corners and I plan on just covering the material with craft felt from Joann fabrics as I did with my broadband traps. As far as space, I would like to conserve as much as possible so I figured tri-traps would be best for me. Here are a few of the questions I have...

1.) In your experience, what material and density is most effective in absorbing low end and easily cut into triangles, Ultratouch (5.5"/8"), OC 703 (2"), or Mineral Wool Board (3")? How much material might be needed to make two 4' tall traps to fill a single 8 foot tall corner?

I have found Ultratouch at a pretty cheap price here... UltraTouch Natural Cotton Fiber Insulation offers superior sound and thermal insulation in a Class-A fire rated product resistant to mold and mildew. I also have the ability to buy 12 OC703 panels (2" thick) for $105 as well, but I wondered how much material might be necessary to fill 4 corners.

2.) I have seen posts about DIY corner/tri-traps not being effective down in the low end 65 Hz and below, is there a certain density or design that is most effective in taming these low frequencies?

Lastly, I would just love to see photos of your DIY tri-trap designs and what challenges you found, what you might do over, etc...

Thanks in advance to any and all comments!

[Ethan Winer]

The key to all fiberglass type bass traps is to make them as large and thick as possible, and to cover as much total corner surface in the room as you can. Remember, rectangle rooms have 12 corners, not just 4.

--Ethan

[Glenn Kuras]

2.) I have seen posts about DIY corner/tri-traps not being effective down in the low end 65 Hz and below, is there a certain density or design that is most effective in taming these low frequencies?

It is hard to say but using OC 703 should be fine when filling the corner.

[DanDan]

703 is well proven and is easier to work with than those others. Ultratouch is not as healthy as you might presume. SuperChunks are very very effective, even at 63Hz. I do have a recent test which shows this which I will post in due course.
Here's an ingenious design. Corner Traps finally finished! - Home Theater Systems - Electronics and Forum - HomeTheaterShack
DD

[Glenn Kuras]

looking forword to your testing

[Hypagen]

Originally Posted by Glenn Kuras

looking forword to your testing

I'm looking forward to the test results too. I know there's a lot of advice recommending filling corners completely i.e. super chunks, but I've not seen any graphs showing before and after results, which would be very interesting, even if if the results are only applicable to the room tested.

[DanDan]

Don't get too excited about my test. It will only show a long boom in the 70 Hz area being diminished by one SSC and almost eliminated by the addition of a second one.
I have previously shown a 34 Hz boom going from 1.3 Seconds down to 0.6 using the bigger 34 inch SSC's. I need no further evidence to confidently say that Studiotips SuperChunks work very well at LF and have significant performance way down, where most won't measure or trust the results.
I didn't do the Straddle panel vs Filled Corner test.
This has been done. Acoustics Forum • View topic - Corner Absorption Comparision test
I can see no reason to repeat or doubt this. I would like to know how the MiniTraps compared , essentially Straddle panels but with a membrane.
Speaking of membranes, I also didn't try my Superchunks with a membrane in front. Sorry....
I will do that some day, when I replace the fabric with something nicer.
From Ethan's tests of FRK and not, I strongly suspect that the Superchunk with membrane will show a significant increase in LF performance. I am no fan of having flat sheets of aluminium and or plastic, eight feet tall all around me when I am mixing. This leads me to suggest that an ultimate SSC would have a membrane fronted by say foam or fibre maybe 25 mm thick to eliminate direct HF bounces. Perhaps this is the Holy Grail of Bass Traps?
DD

[Hypagen]

Thanks for the link DanDan I'd not previously seen this information.

[Glenn Kuras]

Like I have said in the past our Tri Trap in "kind of" like filling a corner so you can "kind of" go off of those numbers. We would love to make a bigger one but if we did we would then have to make it shorter due to shipping.

[drummerboy1533]

Ahhh yes-the loooong wait at the fabric cutting station in Joanns! Nothing manlier than standing with the ladies clutching my multi colored fabric.Then comes the always-asked question from the fabric cutter of what you are making.I'm sure glad it is only on occasion.

[Ethan Winer]

LOL, I'm totally secure in my manliness. Not only do I enjoy buying stuff at Jo-Ann Fabrics, I even carry my wife's purse in public sometimes.

--Ethan

[Glenn Kuras]

Originally Posted by Ethan Winer

LOL, I'm totally secure in my manliness. Not only do I enjoy buying stuff at Jo-Ann Fabrics, I even carry my wife's purse in public sometimes.

--Ethan

Ahhhh how sweet.

[Wiz_Oz]

Originally Posted by Glenn Kuras

Ahhhh how sweet.

Unfortunately though,...his wife is at home...


cheers

Wiz

[Eatin Weenies]

Originally Posted by Glenn Kuras

Like I have said in the past our Tri Trap in "kind of" like filling a corner so you can "kind of" go off of those numbers. We would love to make a bigger one but if we did we would then have to make it shorter due to shipping.

Would it not be possible for you to make say a 24" trihedral trap which could be mounted directly into the high corners (leaving an air in the rear of the design of course) where the walls meet the ceiling, and construct it out of the same materials you currently employ and offer at a relative price point as your other GIK products?

That might solve your size/shipping issue, work in conjunction with your floor standing type model, and look great at a fair price.

Being thoughtfully provoking while I am,

Eatin Weenies

[Eatin Weenies]

Can I infer from your lack of a response to my product query (See post above) means that you are already deep in R&D, developing a light weight, wood framed, price friendly, trihedral ceiling mounted bass trap to compliment your existing line of GIK acoustic treatments?

This would be a commercial product who's day is long since over due, and would be a boon to small studios everywhere, especially where limited floor space and budgets are an issue.

I sincerely hope you will consider adding this item to your catalog in the very near future.

While awaiting your response, I shall be,

Eatin Weenies

[RScott]

Originally Posted by Ethan Winer

The key to all fiberglass type bass traps is to make them as large and thick as possible, and to cover as much total corner surface in the room as you can. Remember, rectangle rooms have 12 corners, not just 4.

--Ethan

So if you had a finite amount of material, would it be better to trap more area or use thicker designs?

Say, you had the option of eight 2" panels or four 4" panels, would covering more surface area (with the eight panels) be the way to go?

[Blind]

surface

[Ethan Winer]

Originally Posted by RScott

So if you had a finite amount of material, would it be better to trap more area or use thicker designs?

More thinner traps is better, though two inches thick is not quite enough for bass traps. I did a test of exactly what you're asking, using twelve 3-inch thick traps versus only six that were 6 inches thick:

Density Report

--Ethan

[2busdriver]

Originally Posted by Ethan Winer

Density Report

--Ethan

Thanks for that!

[Millo 3.1]

Originally Posted by DanDan

Don't get too excited about my test. It will only show a long boom in the 70 Hz area being diminished by one SSC and almost eliminated by the addition of a second one.
I have previously shown a 34 Hz boom going from 1.3 Seconds down to 0.6 using the bigger 34 inch SSC's. I need no further evidence to confidently say that Studiotips SuperChunks work very well at LF and have significant performance way down, where most won't measure or trust the results.
I didn't do the Straddle panel vs Filled Corner test.
This has been done. Acoustics Forum • View topic - Corner Absorption Comparision test
I can see no reason to repeat or doubt this. I would like to know how the MiniTraps compared , essentially Straddle panels but with a membrane.
Speaking of membranes, I also didn't try my Superchunks with a membrane in front. Sorry....
I will do that some day, when I replace the fabric with something nicer.
From Ethan's tests of FRK and not, I strongly suspect that the Superchunk with membrane will show a significant increase in LF performance. I am no fan of having flat sheets of aluminium and or plastic, eight feet tall all around me when I am mixing. This leads me to suggest that an ultimate SSC would have a membrane fronted by say foam or fibre maybe 25 mm thick to eliminate direct HF bounces. Perhaps this is the Holy Grail of Bass Traps?
DD

does that show the megalenrd absorbing more LF? Wow. And yup, it is both huge and expensive but if this is true then it might work. Anyone have any real-world experience of these vs. the superchunks?

Have you experimented w/ your "double-absorber/single-membrane" design?

[Ethan Winer]

Wow, that's an old comparison. Getting only 6 Sabins at 63 Hz no longer seems so impressive given what's available these days.

--Ethan

[Millo 3.1]

Originally Posted by Ethan Winer

Wow, that's an old comparison. Getting only 6 Sabins at 63 Hz no longer seems so impressive given what's available these days.

--Ethan

oopsy...--I just realized I wasn't thinking in the right units... Proves how much of a newbie I am.

I'm off to a gig. Tomorrow evening I'll post a little sorta-general question about the superchunk/membrane idea.

[Millo 3.1]

So, if I want to make a bass trap w/ a membrane, do I want to make sure I have a general idea of what frequencies that membrane is reflecting? Is some sort of readily-available plastic good to act as a membrane? If FRK-covered 705 reflects only very-high freq's, would anyone one to cover also that w/ a thin sheet of foam, so that it doesn't reflect as much?

...I don't know that these questions are for this thread, though, LOL!... INSANE IN THE MEMBRANE!

[DanDan]

Milo. The FRK supplied on 705 etc. is quite heavy. I have read elsewhere that a 4 inch FRK batt resonates at very approximately 250Hz. Certainly I can hear something like this when it tap a hanging panel. I have also read that a 0.5 mil or so sheet of plastic will work just fine. Some have even used clingfilm around homemade tube traps. Even paper should work. Many prefer the brightness which FRK bounces back into the room. I don't, so I recommend a layer of foam or fibre to cut the HF. I suggest 20-30 mm is appropriate. This is not an exact science. In fact sometimes a little science can really get in the way of what is ultimately an ear/taste issue.
DD

[Glenn Kuras]

Originally Posted by DanDan

Milo. The FRK supplied on 705 etc. is quite heavy. I have read elsewhere that a 4 inch FRK batt resonates at very approximately 250Hz. Certainly I can hear something like this when it tap a hanging panel. I have also read that a 0.5 mil or so sheet of plastic will work just fine. Some have even used clingfilm around homemade tube traps. Even paper should work. Many prefer the brightness which FRK bounces back into the room. I don't, so I recommend a layer of foam or fibre to cut the HF. I suggest 20-30 mm is appropriate. This is not an exact science. In fact sometimes a little science can really get in the way of what is ultimately an ear/taste issue.
DD

[DanDan]

Happy Birthday Glenn!
DD

[Glenn Kuras]

Originally Posted by DanDan

Happy Birthday Glenn!
DD

Guess you got the newsletter!!!!!

Thanks but not until Nov 7th. I can't believe I will be 42.

[Millo 3.1]

Originally Posted by DanDan

Milo. The FRK supplied on 705 etc. is quite heavy. I have read elsewhere that a 4 inch FRK batt resonates at very approximately 250Hz. Certainly I can hear something like this when it tap a hanging panel. I have also read that a 0.5 mil or so sheet of plastic will work just fine. Some have even used clingfilm around homemade tube traps. Even paper should work. Many prefer the brightness which FRK bounces back into the room. I don't, so I recommend a layer of foam or fibre to cut the HF. I suggest 20-30 mm is appropriate. This is not an exact science. In fact sometimes a little science can really get in the way of what is ultimately an ear/taste issue.
DD

PERFECT!!! THANKS! This is something that I had been wondering for a while since I started reading about the topic.

[Ethan Winer]

Originally Posted by Glenn Kuras

I can't believe I will be 42.

Youngster!

[Millo 3.1]

Originally Posted by DanDan

0.5 mil

mil = mm, correct? Not "million". I hope so, for the sake of my wallet.

"Clingfilm" = typical kitchen plastic wrap, correct? Sorry, had never heard that term.