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Stacked firewood as rear wall diffusor?
Old 8th August 2020
  #1
Stacked firewood as rear wall diffusor?

Would that roughly do what a diffusor does?

It's a huge drywall, so the bass goes right through.

Thanks.
Old 8th August 2020
  #2
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Jason Foi's Avatar
 

Quote:
Originally Posted by Matteusz View Post
Would that roughly do what a diffusor does?

It's a huge drywall, so the bass goes right through.

Thanks.
What kind of diffuser?

What does a diffusor have to do with bass going through drywall?
Old 8th August 2020
  #3
Gear Nut
 

It's not likely to do anything about the bass leaving through the back wall. There's a potential range of scattering from "kinda gets rid of the flutter echo" to "provides a truly diffuse return from a coherent sound source," and I'm sure it will be somewhere on that continuum. Id imagine the more the end cut angles, wood size, and wood length (how much the out facing ends are offset from each other) are different and randomly placed, the more useful scattering you're going to get. Try not to move termites into your house...
Old 9th August 2020
  #4
Quote:
What kind of diffuser?
The kind that's made out of randomly placed pieces of wood.

Don't know the correct term.

EDIT: skyline diffuser?

Quote:
What does a diffusor have to do with bass going through drywall?
I don't know. Just describing the situation.
Old 9th August 2020
  #5
Quote:
There's a potential range of scattering (...)
So it should do SOME good, and not hurt, I understand.

If I put some randomness into the "sticking out" pattern.


Quote:
Try not to move termites into your house...
It's alive already.

Whatever it is seems to stay inside the stack though.


Thank you, Sir!
Old 9th August 2020
  #6
Any tricks how to stack for maximum effect?


This is where I want to put the firewood in:

(2x2 meter)
Attached Thumbnails
Stacked firewood as rear wall diffusor?-kallax5x5.jpg  
Old 9th August 2020
  #7
Gear Nut
 

I think you're sort of shooting in the dark here, while you'll get some sort of scattering with this plan, it might end up pretty wonky. 1- if your firewood is "normal sized," i.e. 4-6" pieces, the effect may not go as high as you want, and you're taking a lot of room for a fairly iffy treatment. Do you know this is what your room needs? Is your listening spot far enough away to benefit from scattering/diffusion? Might you be better off with other things in that space, like broadband absorption, bass trapping, or a mix?

I'm not an acoustician, but if you're going to do it I'd say smaller split wood, and as much random variation in length as you can get and still have them hold themselves up when you stack them pushed as far back as possible.
Old 9th August 2020
  #8
Lives for gear
 
Jason Foi's Avatar
 

Quote:
Originally Posted by Matteusz View Post
Any tricks how to stack for maximum effect?


This is where I want to put the firewood in:

(2x2 meter)
Ok, well if you want a skyline, make a skyline. Its not going to do much, if anything, for isolating or scattering LF. To scatter LF it would need to be HUGE. Use the following link to build it. You need pieces to be as uniform in diameter as nature allows. Then cut lengths according to plan.
http://www.mh-audio.nl/Acoustics/DiffusorCalculator.asp

Note: your room needs to be big enough for this to work. If a control room, LP should be 3x the wavelength of the lowest diffused frequency away.

Good luck
Old 9th August 2020
  #9
Thanks, guys.

It's a big room, 8x10m. 3 to 4m high, angled. EDIT: forgot to attach pic, see next post

It's pretty good acoustically, I just have this HUGE naked drywall about 3m behind me.

Quote:
Do you know this is what your room needs?


Probably I should make some measurements first.

Quote:
LP should be 3x the wavelength of the lowest diffused frequency away
What's LP?


Bass trapping, it seems to me, is mostly taken care of by the big room behind the drywall. Maybe I'm fooling myself here..


Building a proper diffuser myself, I don't have the means at the time.
Also I'm not hanging anything on that drywall.

I don't trust it.


Thanks!
Old 9th August 2020
  #10
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edva's Avatar
I think it's a good idea and well worth trying. Maybe just some concern about insects coming in with the firewood.
But people have used bookshelves and similar for DIY diffusion for many years, so I don't see anything wrong with trying this idea.
IMHO. Good luck.
Old 9th August 2020
  #11
Here's the room.

The firewood is right now stacked all the way across the lower window side.

1m high, 8m long. And already full of insects.
Attached Thumbnails
Stacked firewood as rear wall diffusor?-my-room.jpg  
Old 9th August 2020
  #12
Lives for gear
 
Jason Foi's Avatar
 

Quote:
Originally Posted by Matteusz View Post
Thanks, guys.

It's a big room, 8x10m. 3 to 4m high, angled. EDIT: forgot to attach pic, see next post

It's pretty good acoustically, I just have this HUGE naked drywall about 3m behind me.





Probably I should make some measurements first.



What's LP?


Bass trapping, it seems to me, is mostly taken care of by the big room behind the drywall. Maybe I'm fooling myself here..


Building a proper diffuser myself, I don't have the means at the time.
Also I'm not hanging anything on that drywall.

I don't trust it.


Thanks!
LP = listening position

The center of the room is typically a bad spot as its usually in a huge null.... how did you determine your location?
Old 9th August 2020
  #13
Quote:
The center of the room is typically a bad spot as its usually in a huge null.... how did you determine your location?
I just put a table next to the column in the middle.

Turned out later I'm sitting pretty much at the always recommended 38% of the way.


I'm also off-center to the side, which is not recommended.

But it's such a big room, I guess that's cool.


I got 25 mยฒ of windows.
Old 9th August 2020
  #14
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Starlight's Avatar
 

Quote:
Originally Posted by Matteusz View Post
I'm sitting pretty much at the always recommended 38% of the way.
Don't forget that 38% is an often recommended position to start measuring to find where the sweet spot is in your room with your setup and your treatment.
Old 10th August 2020
  #15
I'd be worried about sapwood as a craftsman myself, you don't want deathwatch beetle getting inside a building or any woodworm of any kind in case they break free and get into structural joists, it can seriously compromise and even destroy buildings, maybe not something you have thought of but it's something you should consider before going ahead.

I would build 2D skyline diffusers instead, they are quite an easy build, just get some 2x2 and stick it on plywood or OSB and attach it to your back wall, there are plenty of free plans online.
Old 10th August 2020
  #16
Quote:
Originally Posted by pencilextremist View Post
I'd be worried about sapwood as a craftsman myself, you don't want deathwatch beetle getting inside a building or any woodworm of any kind in case they break free and get into structural joists, it can seriously compromise and even destroy buildings, maybe not something you have thought of (..)
No, not until now.


Thanks, I will keep that in mind.
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