My Bass Trap concept?What's your thoughts?

[Glenn Kuras]

15cm thick if the panel is straddling the corner should work. Just plan on making a lot of them. Not sure on our membrane idea but it may be fine. The only way to know is to test it before and after.

[Call_me_Switters]

Originally Posted by Glenn Kuras

15cm thick if the panel is straddling the corner should work. Just plan on making a lot of them. Not sure on our membrane idea but it may be fine. The only way to know is to test it before and after.

I read some good staff about the membrane on low frequencies. Also i read a thread for a guy that had wool packed in some plastic bags and you told him put it as is (with the bags) in the corners and it might work nice! So I believe that my more sophisticated (LOL) design might work as well!

Would you suggest to put breathable fabric around instead? I don't know if I can compare fabric VS vinyl in real world situation with hearable results!

What do you mean "straddling the corners"? I will try to put them as close as possible in every corner and as long as they are transportable i believe that it will not be a problem!

My method of testing is a bit old school.
I sweep an oscillator and I see where the bass booms and where it nulls by ear. It is not very accurate I know, but I prefer to know average how it sounds instead of know exactly a number in Hz!
(i don't have also measurement mic and i really hate the idea of buying this crappy Behringer or give real money for a mic that nobody will sing on it!)

[John Suitcase]

Check out the Attack Wall concept, there are some good posts about DIY approaches to this concept, as well. I'm not an acoustical engineer, but it seems like a viable option, if fitted corner traps are out of the question.

[Glenn Kuras]

Straddling as in the panel going 45 degrees across the corner.

[Call_me_Switters]

Originally Posted by John Suitcase

Check out the Attack Wall concept, there are some good posts about DIY approaches to this concept, as well. I'm not an acoustical engineer, but it seems like a viable option, if fitted corner traps are out of the question.

Thanks mate!
I found some DIY concepts that are close to mine. I realized and i know that "they are absorbers they don't make magic beans", but I just hope to tidy a bit my low end that seems more present because of "broadband" absorbers fitted in the room.

[Call_me_Switters]

Originally Posted by Glenn Kuras

Straddling as in the panel going 45 degrees across the corner.

OK!Got it!
i will start building and I will come back with pics, info the results!

Thank you!

[Glenn Kuras]

BTW the membrane idea I "think" would be fine but then again I have tested a lot of membrane ideas in our test/lab room and they failed. The best i can tell you is "maybe" and if that is not good enough then don't use it. BTW if anything it might just cut off the a bit lower then you would like.

[Call_me_Switters]

I appreciate your careful advice. I will put the membrane and if it seems not to work as I expect or as I want,I will try to put some fabric and I will chose what fails less! ;-) But I keep myself optimistic till that time!

[DanDan]

Ethan Winer's historic tests ;-) showed a slight LF absorption increase in FRK 705 vs naked 705.
This has also been seen in Lab tests. However this membrane is fully bonded to the board, to the extent that one might say they are a combined item. A stiffened board if you will. Simply wrapping or hanging membranes on fibre is not the same thing and as Glenn has shared, unlikely to succeed.
A helpful GS tried various fronts on SSC's way back. No measured result at LF, but one does get some extra HF decay. This could be wanted or really annoying depending. Ping.....

I would go with the standard SSC. The little triangle frames are the key to success. Corner Traps finally finished! - Home Theater Forum and Systems - HomeTheaterShack.com

Better still go for the very high performance VPR My Experiment with a Metal Panel Absorber

Nobel for Malala

DD

[Glenn Kuras]

A stiffened board if you will. Simply wrapping or hanging membranes on fibre is not the same thing and as Glenn has shared, unlikely to succeed.

Can't go into to much detail but our new FRL line uses a membrane that is stiff so it is possible.

Room test

empty room


Treated


Placement


10 FRL wedge units
3 FRL panel units
Room: 13'x17'x8'

[Call_me_Switters]

Glenn, your new stuff seems that it could make wonders in a small space!

Dandan, I have built some not as deep VPRs that work good on the upper spectrum but they dont go real low and I cant fit them in the corners because in one is a window,in the other the main door,in the 3rd the booth door and in the last one the machine closet!!!

I can go with the well tied stretched and attached as tight as possible to the sheep wool.I will try to make it as stiffened as possible and tight like...a combined material!
You believe that this might improve the design?
As I mentioned before triangles are not an option!
So looking for the best second solution!
Should I leave inside some air gap or fill it up!?

[DanDan]

Nice results Glenn.

Sorry switters I speed read. SuperChunks do not have to be triangular.
Take a look at Glenn's SoffiTraps.
Any shape filled with fibre, in a corner will be effective.
Fill it completely with light fibre.
Flat traps on one side of the corner, e.g. if there is a door issue, work too, just not as well as straddling or of course filled.

DD

[GIK Acoustics]

Originally Posted by DanDan

Flat traps on one side of the corner, e.g. if there is a door issue, work too, just not as well as straddling or of course filled.

+1

Also, wall-to-ceiling corners are very viable as well and usually don't get in the way of much in a room, so I would certainly consider that as well.

[John Suitcase]

Originally Posted by GIK Acoustics

+1

Also, wall-to-ceiling corners are very viable as well and usually don't get in the way of much in a room, so I would certainly consider that as well.

I was just going to add this, we get fixated on vertical corners, but floor to wall, and wall to ceiling corners are good, and in some cases even more effective.

[Call_me_Switters]

So...what i learned!
I will go for my cylindrical bass trap concept for the vertical corners and later i will try some wall to ceiling flat trap stiffened in the corner.
I will keep the outside membrane in the cylindrical trap but i will glue it in the wool and i will keep it well stretched.
Finally i will fill it with wool without leaving air gap.

Are all this correct,and should i proceed gentlemen?

[DanDan]

Switters, the inclusion of a membrane may or may not be useful. It is unknown. Also gluing to light insulation is an unknown. The tested bonded membranes were on 100KG 'boards'. When you thump such a panel it has a sort of resonant thud.
If you goal is to have some HF reflected back into the room, then wooden slats with gaps would be a very good way to go. You could use Newell's simple 345 sequence or boggy's more sophisticated one(s). Slats facing over fabric/fibre is robust, looks great, and provides a properly scattered or even diffused HF return.

DD

[Glenn Kuras]

If you goal is to have some HF reflected back into the room, then wooden slats with gaps would be a very good way to go. You could use Newell's simple 345 sequence or boggy's more sophisticated one(s). Slats facing over fabric/fibre is robust, looks great, and provides a properly scattered or even diffused HF return.

+1.. Just to add you can put it under the cloth also.

[Call_me_Switters]

Originally Posted by DanDan

Switters, the inclusion of a membrane may or may not be useful. It is unknown. Also gluing to light insulation is an unknown. The tested bonded membranes were on 100KG 'boards'. When you thump such a panel it has a sort of resonant thud.
If you goal is to have some HF reflected back into the room, then wooden slats with gaps would be a very good way to go. You could use Newell's simple 345 sequence or boggy's more sophisticated one(s). Slats facing over fabric/fibre is robust, looks great, and provides a properly scattered or even diffused HF return.

DD

Dandan I need a cylindrical movable device!That's my issue!I know and i have build absorbers and flat bass traps for other places in the room. But in this situation I am looking for the best solution so go cylindrical and movable!Please any comments on a construction like this?

[DanDan]

If you can find a industrial supplier of fibre they should have the rigid circular fibreglass. You could pretty much copy Tube Traps.
DIY Tube Traps

DD

[Call_me_Switters]

Exactly this I wanted to mimic from the beginning!
But this design uses something like a membrane attached to the fiber and air gap inside.
I ordered the wood covers, instead of fiber glass I have a more effective sheep wool that i plan to curb it around and for membrane I intend to use vinyl.
Also a wooden connector between top and bottom covers to make the construction more rugged.
So...should I fill it up or leave the air gap?
And in this case the design with the membrane is tested with good results?

[DanDan]

The advantage of the rigid fibreglass is that you need no frame. I have seen no sound absorption tests on sheeps wool. I don't understand how you will make a tube out of that, but in any case I reckon fill it up. The circular fibreglass is quite dense so it is a very different principle at work. For the same reasons there is no way of knowing if your membrane will help or hinder or do nothing.

DD

[Call_me_Switters]

I have seen very impressive graphs for the sheep wool and it also dont release fibers in the air.I am positive that i can curb it and with two pieces make a tube that I can hold with the vinyl membrane and the wooden inside spool. I will fill it up and maybe put some cloth around for cosmetic reasons. I am a bit optimistic about it somehow without been an expert..Thanks DanDan for your distilled wisdom!