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[woodnote]

Yes
For example, "0" mean non-existance of slat (strip), "1" mean existance of slat. You may start from first position (000) and build your diffuser following sequence from 000 to 127. When you finish (and you may finish at any position), you may continue sequence at second absorber.
yes
It is possible to build successfull binary diffuser without gaps, but gaps enables more air circulation, and slightly more expressed slat absorber characteristic.
Yes and yes. I choose slats thickness from 1/8"-1/2" (what i can find on the market in some area), and I don't change chosen thickness in one particular binary diffuser... binary diffusers don't have different thickness of slats. To be clear, diffusers of this construction may have different thickness of slats, but they can't be named "binary" anymore.

Thanks, its all clear now. so i decide on a slat width and that will be a single unit. if i multiply it by 127, that will be the width of the whole diffuser.

how would you suggest mounting the slats on the absorption material? glue? or just make the whole diffuser frame tight enough to hold it all together?

i want to ask for your opinion on something i just bumped into: "The helmholtz resonator", i assume you already know what it is. its similar to what you're suggesting in the design, and in the fact that it both absorbs and diffuses. the absorption material not as visible as in yours and the wood slats take much more surface area. every wood slat is in another width so its tuned to different frequencies. so you can have a variety of slat widths in the same frame so it can be tuned to a whole range of frequencies.

i wanted to know what do you think of this helmholtz resonator comparing to what you're suggesting for my situation (small room, dyi..).

a picture of the helmholtz resonator:

[boggy]

Thanks, its all clear now. so i decide on a slat width and that will be a single unit. if i multiply it by 127, that will be the width of the whole diffuser.

127 members of sequence is only part of sequence, number of it is inifinity. I hope that 127 can be enough for most applications, then you don't need to use it all. Find wooden strips that you like, and start to mount it... it's not needed to mount all 127, you can cut sequence where you need.

how would you suggest mounting the slats on the absorption material? glue? or just make the whole diffuser frame tight enough to hold it all together?

I always build wooden frame in front of absorber, then i cover absorber and frame with  (air transparent) fabric, then i fix wooden strips to wooden frame under fabric. You can use nails, screws...

i want to ask for your opinion on something i just bumped into: "The helmholtz resonator", i assume you already know what it is. its similar to what you're suggesting in the design, and in the fact that it both absorbs and diffuses. the absorption material not as visible as in yours and the wood slats takes much more surface area. every wood slat is in another width so its tuned to different frequencies. so you can have a variety of slot width in the same frame so it can be tuned to a whole range of frequencies.

Yes... I understand

i wanted to know what fo you think of this helmholtz resonator comparing to what you're suggesting for my situation (small room, dyi..).

Honestly, I don't believe this construction is much applicable and/or effective in small rooms, then I never used it.
Binary diffusers can have a large air-transparent area, more than 50% with gap applied, then I'm sure that wideband, low frequency absorber isn't much degraded.

[woodnote]

I always build wooden frame in front of absorber, then i cover absorber and frame with  (air transparent) fabric, then i fix wooden strips to wooden frame under fabric. You can use nails, screws...

So does it matter if the wooden stripes are touching the fabric (that wraps the fiberglass) or if there's a little gap (2-4mm) between the stripes and the fabric?

[boggy]

So does it matter if the wooden stripes are touching the fabric (that wraps the fiberglass) or if there's a little gap (2-4mm) between the stripes and the fabric?

You are right, small gap between fabric and slats is better.

[woodnote]

You are right, small gap between fabric and slats is better.

Thank you, you've been very helpful and provided an answer for every little question i had.
i appreciate it very much!

[woodnote]

You are right, small gap between fabric and slats is better.

^i only quoted so you'll get a notification^

A question:

When i'm making those absorbers with the wooden stripes on top, should i make an air cavity as part of the panel (wooden closed space behind the panel)? or should i just make it as a regular absorber with a gap from the wall?

[boggy]

^i only quoted so you'll get a notification^

A question:

When i'm making those absorbers with the wooden stripes on top, should i make an air cavity as part of the panel (wooden closed space behind the panel)? or should i just make it as a regular absorber with a gap from the wall?

Do this in a easier way to you, there may be differences, but I believe that they are negligible.
Small gap between strips and fabric is needed to avoid noise that wooden strips may produce when touch fabric, because of vibrations (free fabric streched on the frame may vibrate too!)... it's not a problem if you have one small wooden strip in studio that vibrate and touch something near... but if you have hundreds... that may be a problem

[woodnote]

Do this in a easier way to you, there may be differences, but I believe that they are negligible.
Small gap between strips and fabric is needed to avoid noise that wooden strips may produce when touch fabric, because of vibrations (free fabric streched on the frame may vibrate too!)... it's not a problem if you have one small wooden strip in studio that vibrate and touch something near... but if you have hundreds... that may be a problem

oh sorry you didn't understand, i wasn't asking about this, i was just quoting your comment so you get a notification and see my reply.

i wanted to know if i need to do a sealed air cavity behind the while panel, or just do it like a regular absorber panel with a gap from the wall.

[boggy]

oh sorry you didn't understand, i wasn't asking about this, i was just quoting your comment so you get a notification and see my reply.

i wanted to know if i need to do a sealed air cavity behind the while panel, or just do it like a regular absorber panel with a gap from the wall.

I see no need for any sealing.
Mount your absorbing panel as you planned, with or without gap from wall.

[woodnote]

I see no need for any sealing.
Mount your absorbing panel as you planned, with or without gap from wall.

Ok thanks!

[woodnote]

127 members of sequence is only part of sequence, number of it is inifinity. I hope that 127 can be enough for most applications, then you don't need to use it all. Find wooden strips that you like, and start to mount it... it's not needed to mount all 127, you can cut sequence where you need.

A question about this. i'm making two panels, so on the second panel should i start the sequence from the beginning or can i also continue from the middle of the sequence?

Another thing, i'm thinking of doing a third wide panel (120x60cm instead of 60x120cm - WxH). so should i do the slats vertical (more slats, but short ones) or horizontal (less slats, but longer ones)?

[boggy]

A question about this. i'm making two panels, so on the second panel should i start the sequence from the beginning or can i also continue from the middle of the sequence?

Continue from the point where you ended with previous.
Start from your acoustic listening axis, and go to left and right symmetrically.
You may use same sequence symmetrical to listening axis, but try not to use same sequence in only one side, if you need more than 127 positions, please ask, we will try to make longer sequence.

Another thing, i'm thinking of doing a third wide panel (120x60cm instead of 60x120cm - WxH). so should i do the slats vertical (more slats, but short ones) or horizontal (less slats, but longer ones)?

If you like full acoustical functionality use vertical orientation for front, back, left and right wall absorbers. If you like aesthetic go horizontal for all of it.
For ceiling use horizontal orientation (when you sit at listening position, look at speakers, then look up at ceiling)


EDIT: If you not sure, draw simplified situation in Sketchup, and attach picture here, i will check it.

[woodnote]

EDIT: If you not sure, draw simplified situation in Sketchup, and attach picture here, i will check it.

yeh that's exactly what i'm doing. i understood what you said about my second question but not the first. wait i'll make it clearer with the sketch.

[woodnote]

EDIT: If you not sure, draw simplified situation in Sketchup, and attach picture here, i will check it.

Here is how i thought it should be.

Lets say the sequence is:

Code: [Select]

position 000: 1
position 001: 1
position 002: 0
position 003: 1
position 004: 0
position 005: 0
position 006: 1
position 007: 0
Here is a picture and the skatchup file.
I did the slats very wide so its easier for us to see.

Download MLS.skp

EDIT: if you want to see the whole room plan, i did an accurate sketch (the slats are in a random order in this room sketch). don't mind the mixing spot, just the recording spot: Download myroom.skp

[boggy]

Here it is.
You start from your right (for example) absorber and count to right. Also you start your left side absorber and count to left, same as right but mirrored.
If you have absorbers behind your loudspeakers, then do same, but start from this absorbers.
If you build soffit, it's same, you always start from first absorber at your right or left side, and count to right or left respectively.
Don't repeat sequence on one whole side, when you finish sequence on one absorber, then continue sequence on the next.
Your left and your right side in room must be symmetrical, and your binary diffuser slats may be mirrored.

EDIT:
.skp file isnt allowed as attachment here, zip, rar, 7z too.
I used "your" upload service

here are a modified .skp file
http://solidfiles.com/d/e1197/


EDIT2:
If you don't need binary diffusers for control room, but for recording room, it's not needed to follow symmetry, start from where you like, and count around whole room.