diffuser primes and frequency range

jrubbernek · 30th June 2009

Hi I'm thinking about making DIY diffuser, I just don't know which prime and what type and what frequencies I wanna diffuse.....is there any way to figure out what frequency range I wanna diffuse, so I can figure out the design of the diffuser I am going to make...

thanks....

check out my Lego diffuser I just made for fun...it cost only 18dolars, and weigh around 5 kilos....that is very light...!!!!!

it's about 1.5feet in length and width

Skyline made of Lego blocks

Glenn Kuras · 30th June 2009

I would just stick with the standard 7 root QRD.

jrubbernek · 1st July 2009

Quote:

Originally Posted by Glenn Kuras

I would just stick with the standard 7 root QRD.

thanks for the reply...but how to figure out which frequency the diffuse, so I know the size and depth?

jwl · 1st July 2009

Well, the lower the frequency to which they diffuse, the deeper the diffusor. How many legos do you have?

Diffusion is most common between about 1k and about 5k. Sometimes lower, sometimes higher, sometimes both.

bpape · 1st July 2009

I'd agree with the 7 root. If you can use about 6" thickness, you can effectively cover a range from the mid 500's to around 3.5kHz.

Bryan

Nordenstam · 2nd July 2009

Why the root seven recommendation? What benefit is there over the 2D diffusors?

Nordenstam · 5th July 2009

Bumpy.. Not to to bite anyone or anything like that, but I do find the recommendations above a bit odd. QRD's are simpler to build for sure, but if the means are there to go with PRD's - why not? The range of scattering both above and below the design frequency is better with PRD's and they need less distance from the listening position. So if practical implementation is a non-issue, I'd wager to say that PRD's are better.

Aside from the odd situations where diffusion in one direction and specular reflections in the other direction is desired.

*edt: this is AFAIK. I'd love to stand corrected if there's anything wrong in my understanding of this!

30th June 2009	#1
jrubbernek Gear maniac Joined: May 2009 Posts: 284 Thread Starter	diffuser primes and frequency range Hi I'm thinking about making DIY diffuser, I just don't know which prime and what type and what frequencies I wanna diffuse.....is there any way to figure out what frequency range I wanna diffuse, so I can figure out the design of the diffuser I am going to make... thanks.... check out my Lego diffuser I just made for fun...it cost only 18dolars, and weigh around 5 kilos....that is very light...!!!!! it's about 1.5feet in length and width Skyline made of Lego blocks

1st July 2009	#4
jwl Lives for gear Joined: Jul 2006 Location: southern Maine Posts: 1,309	Well, the lower the frequency to which they diffuse, the deeper the diffusor. How many legos do you have? Diffusion is most common between about 1k and about 5k. Sometimes lower, sometimes higher, sometimes both. __________________ The acoustic treatment experts

1st July 2009	#5
bpape Lives for gear Joined: Jul 2005 Location: St. Louis(Wildwood), MO Posts: 764	I'd agree with the 7 root. If you can use about 6" thickness, you can effectively cover a range from the mid 500's to around 3.5kHz. Bryan __________________ I am serious, and don't call me Shirley Bryan Pape Lead Acoustical Designer GIK Acoustics

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30th June 2009	#2
Glenn Kuras Gear Guru Joined: Jul 2005 Location: Atlanta, GA Posts: 11,992	I would just stick with the standard 7 root QRD.

2nd July 2009	#6
Nordenstam Lives for gear Joined: Aug 2005 Location: Norway Posts: 1,741	Why the root seven recommendation? What benefit is there over the 2D diffusors?

5th July 2009	#7
Nordenstam Lives for gear Joined: Aug 2005 Location: Norway Posts: 1,741	Bumpy.. Not to to bite anyone or anything like that, but I do find the recommendations above a bit odd. QRD's are simpler to build for sure, but if the means are there to go with PRD's - why not? The range of scattering both above and below the design frequency is better with PRD's and they need less distance from the listening position. So if practical implementation is a non-issue, I'd wager to say that PRD's are better. Aside from the odd situations where diffusion in one direction and specular reflections in the other direction is desired. *edt: this is AFAIK. I'd love to stand corrected if there's anything wrong in my understanding of this!