Scatter plates?

[nathan_h]

Several web searches have yielded mentions of DIY scatter plate designs (for placing in front on a DIY absorption panel made of OC703) but so far I haven't seen anyone with data about what kind of dimensions the openings should be.

I'm trying to keep it simple.

Was planning to use a router to cut out long slats from a 1/8th inch piece of plywood that will go in front of the fiberglass.

Any proven design principles I should follow?

Like, “1/2 inch openings separated by 1/2 inch of solid material”, or something like that?

I would guess the math is pretty definitive about the size of the openings to allow absorption of (for example) the full vocal range, while reflecting stuff above that range?

But I don’t trust my understanding of how a scatter plate works and of wavelengths enough to feel confident I know the right dimensions.

 

[TheWarrior]

Several web searches have yielded mentions of DIY scatter plate designs (for placing in front on a DIY absorption panel made of OC703) but so far I haven't seen anyone with data about what kind of dimensions the openings should be.

I'm trying to keep it simple.

Was planning to use a router to cut out long slats from a 1/8th inch piece of plywood that will go in front of the fiberglass.

Any proven design principles I should follow?

Like, “1/2 inch openings separated by 1/2 inch of solid material”, or something like that?

I would guess the math is pretty definitive about the size of the openings to allow absorption of (for example) the full vocal range, while reflecting stuff above that range?

But I don’t trust my understanding of how a scatter plate works and of wavelengths enough to feel confident I know the right dimensions.

It's all about turning one solid angle reflection into many. *Random* is the key! Own any books? A bookshelf is often the most economical 'diffusor' you can have!

But as with any room treatment / room 'correction', you're flying blind without accurate, high resolution measurements.

(try a book shelf!)

 

[ryanosaur]

Pics or it doesn't exist!

Skyline Diffuser:


Stepped and Fractal:

Sound Diffusers 101: Free Designs for DIY Diffuser Panels

DIY Sound Diffuser Blueprints—Free designs for optimized diffuser panels & fractal sound diffusers. Come download them and learn about acoustic diffusion!

arqen.com

Slats:

Room treatments are dangerous if you don't know what you are doing. I've seen too many people say they treated their rooms only to throw most of it away once they learned more about how detrimental the effects can be.
@TheWarrior is spot on by saying you need accurate room measurements before you even begin trying... and then you still need to understand what the effects of different Aborption, Diffusion and reflection can yield.
The Master Handbook Of Acoustics is a great resource if you are interested in learning about any of this.

 

[Pogre]

You know, this is really an area I haven't done much research into. Traps, panels, diffusers... I do believe I've squeezed about as much as I can from my system and speakers with what I have. Room treatments do interest me, but I'd have no clue where to even start. Is this something you can figure out based on room measurements? It seems like something you'd have a pro come out to evaluate and figure out what/where I'd need something, if anything.

 

[Pogre]

Pics or it doesn't exist!

Skyline Diffuser:


Stepped and Fractal:

Sound Diffusers 101: Free Designs for DIY Diffuser Panels

DIY Sound Diffuser Blueprints—Free designs for optimized diffuser panels & fractal sound diffusers. Come download them and learn about acoustic diffusion!

arqen.com

Slats:
View attachment 44758

Room treatments are dangerous if you don't know what you are doing. I've seen too many people say they treated their rooms only to throw most of it away once they learned more about how detrimental the effects can be.
@TheWarrior is spot on by saying you need accurate room measurements before you even begin trying... and then you still need to understand what the effects of different Aborption, Diffusion and reflection can yield.
The Master Handbook Of Acoustics is a great resource if you are interested in learning about any of this.

Yeah... pretty much why I haven't tried to DIY something up. Like I said above, I wouldn't even know where to start and would probably do more harm than good.

 

[Blue2kid3]

I'm part of the camp that unless you have a specific problem in your room ignore treatment, energy can't be destroyed but converted I take this to believe if you're just flying blind with treatment you can/will make one room error much worse.

 

[nathan_h]

I’ve got both absorption and diffusion in place in concert with consultation from GIK and measurements and recommendations from Accucal. At the time GIK recommended the diffusion be of the combo scatter plate & absorption, but had a limited selection and prices were high since they were new to their lineup. So I went with their absorption panels and some diffusion from another vendor.

Im ready to follow the advice of these professionals now but since what I have these days is more time than money, and some woodworking skills, I’m hoping to DIY the next step.

The panels were the biggest upgrade my system ever had. Spending a grand on better amps made close to zero impact. Spending that on panels was astonishingly impactful in terms of decay times, and clarity.

 

[ryanosaur]

If you are interested in the DIY approach, I would still strongly recommend the Acoustics book I mentioned above. Super informative, and you do not have to have a Doctorate in Physics.

Also, check out the link above for arqen.com. I don't recall if they do the type of panel you are discussing, but there is a lot of info there that may be helpful.
I will likely be doing a Stepped Diffuser for part of my back wall at some point. It is a ways away, though. Too many other pressing projects, from my Hypex Amps to Subwoofer Summer!

 

[nathan_h]

Thanks yes while arqen doesn’t do scatter plate types it looks like interesting stuff. Their email server is offline so I wasn’t able to download any plans to see the details. But I’ll check again later to see if their system is back online.

I too like Alton’s book. I ended up getting more practical learning from Toole‘s stuff but that says more about my own challenges than about the quality of the scholarship!

I don’t recall scatterplate info in there, but it has been a long time since I read it. I’ll have to dig it back up and review.

 

[nathan_h]

Alas I check and Alton’s work tangentially talks about this but still requires me to know more than I do.

 

[ryanosaur]

Thanks yes while arqen doesn’t do scatter plate types it looks like interesting stuff. Their email server is offline so I wasn’t able to download any plans to see the details. But I’ll check again later to see if their system is back online.

I too like Alton’s book. I ended up getting more practical learning from Toole‘s stuff but that says more about my own challenges than about the quality of the scholarship!

I don’t recall scatterplate info in there, but it has been a long time since I read it. I’ll have to dig it back up and review.

I don't necessarily recall the scatterplates, but they do have several other discussions about determining the frequencies affected by several of the techniques for both Absorption and Diffusion..
I haven't read Toole yet: have it and it is cued up for when I finish the Master Handbook!

 

[ryanosaur]

Alas I check and Alton’s work tangentially talks about this but still requires me to know more than I do.

View attachment 44761

This is why I want to do a stepped diffuser for the back... Hopefully Arqen didn't go offline completely. I did have some of the resources, but dunno if I do still. I'll have to look. At least using the plan I had seen, its just a matter of following the pattern.
The Fractal diffuser was much more involved.
And though the Skyline Diffusers are cool, still a good amount of work, and as I understand, they get real heavy.


Regardless, it's good to know that you understand the basics involved here... all too often people talk about treating with no understanding of how, why or what. Very refreshing!
Cheers!!!

 

[nathan_h]

These are the cheap ones I crafted at the time.....to augment the absorption panels.

Id like to replace these with the combo panels as per the original recommendation.

 

[ryanosaur]

Ah, You did some Step-type diffusers before. How did they work for you in those frames?

 

[nathan_h]

Very little impact probably because of the modest depth. I’ve since learned that to work well more like six or eight inch depth is necessary, but these are at most about 2 inches.....the boxes are 3.5 inches deep.

 

[highfigh]

BTW- if anyone wants to look for the Master Handbook of Acoustics, search using the title, or the author's full name, which is F. Alton Everest. Alton is the middle name.

Did you crunch the numbers after measuring the room's response for RT60 and dispersion, or are you making the diffusion panels with some random design that doesn't have any relation to the actual problems? Guessing can only work by accident.

 

[highfigh]

Very little impact probably because of the modest depth. I’ve since learned that to work well more like six or eight inch depth is necessary, but these are at most about 2 inches.....the boxes are 3.5 inches deep.

If you look at the face of that panel, most of it is a large, flat surface that faces the source of the sound. Minimize the larger surfaces and I bet it would work better. You can cut the exposed edges at an angle and vary the direction, too- just don't use the same angle or direction for all of them.

 

[highfigh]

The Master Handbook Of Acoustics is a great resource if you are interested in learning about any of this.

You have a copy? Which edition?

I should check a newer one for additional info- IIRC, my copy is second edition, that I bought at Consumer Electronics Show in about 1981.

 

[Ren Kitchener]

A good start would be to look a some studio control rooms online - there are solutions they use that are simple and very effective. Drum booths are also interesting - those have to deal with all frequencies and volumes. The best is looking around post production rooms - but there aren't many pictures of those.

 

[ryanosaur]

You have a copy? Which edition?

I should check a newer one for additional info- IIRC, my copy is second edition, that I bought at Consumer Electronics Show in about 1981.

I have the latest, 6th Ed.
Master Handbook of Acoustics, Sixth Edition https://www.amazon.com/dp/0071841040/ref=cm_sw_r_cp_api_glt_fabc_EBYHD95XY2F3QQCKTRTW