[drummermitchell]

I see few companies making higher prime number QRD diffusers.
Usually we'll see 7,15,ect.
Now I know it costs more to build+ shipping ect.
Wouldn't higher prime like 19 or 37 be more advantageous than say a prime 7 even if you use a group of 7's together.

Seems by what I've read it is better to have a larger prime diffuser than grouping smaller primes together.

[jriggy]

I have wondered this recently as well...

[drummermitchell]

I do understand that selling smaller is better for the customer as far as shipping and build,but I'm more concerned with the diffusion properties.
Compare say a prime 43 with a prime 7 in a two channel situation.
Wonder which would be more pleasing to the ear.
I see on Ethan's site in one room he has all RT diffusors all around the room(excluding 1st reflection points)and corners,and bass traps underneath.
They are all the far diffusors with the same amount of wells in each.
I'm sure Ethan or Bryan have experimented with other types of diffusors besides their own.
I believe Gik uses a 7 root diffusor,maybe bigger is better,hopefully we'll get a reply.

[srlaudio]

I for one, make them!

Allen Rumbaugh
SRL Acoustics
www.srlacoustics.com

[bpape]

We do 2 different 7 roots and a 13 root.  Higher roots have benefits and drawbacks.

Higher roots at reasonable sizes require narrower wells which at the same time raises both the upper and lower limit of the diffusion.   Higher roots also tend to scatter more smoothly.

The lower roots allow lower frequency diffusion (not bass certainly but lower) which allows them to, in our opinion, work more in the 'guts' of the music rather than just in the higher range.

Certainly the lower roots are more cost effective to manufacture and for the consumer.  There really is no best, more a matter of what is appropriate for what you're trying to do in a certain situation.

Bryan

[drummermitchell]

Hi Bryan,thx.hopefully to open up the room some more(physiologically).
To give the impression that it seems bigger than 12 X19X7,
Coming out of the closet , to the livingroom so to speak without messing things up.
That sentence was a joke as i'm happily married .

[drummermitchell]

Here I thought the acoustic circle was for discussing anything to do with room acoustics ,oh well easier to just pick up the phone.
If it's somebody advertising then that post should be moved or deleted not the discussion on room treatment after all it is the acoustic circle or is it anymore.

[SoCalWJS]

We do 2 different 7 roots and a 13 root.  Higher roots have benefits and drawbacks.

Higher roots at reasonable sizes require narrower wells which at the same time raises both the upper and lower limit of the diffusion.   Higher roots also tend to scatter more smoothly.

The lower roots allow lower frequency diffusion (not bass certainly but lower) which allows them to, in our opinion, work more in the 'guts' of the music rather than just in the higher range.

Certainly the lower roots are more cost effective to manufacture and for the consumer.  There really is no best, more a matter of what is appropriate for what you're trying to do in a certain situation.

Bryan

What are the frequencies involved with the lower roots? Is there a "rule of thumb"? If you could share which primes work best at a given frequency range, that would be a great starting place for future considerations.

I am inclined to agree that when the upper bass/midrange up through soprano female vocals are addressed, that would do me the most good, but having that "air" and "ambience" of the higher frequencies would be nice as well - just costs more

[Big Red Machine]

As you change the wells in this model you can see the frequencies adjust or you can adjust for frequency and it will give you a size.

http://www.subwoofer-builder.com/qrdude.htm

I made 53's for my room.  Should have made them on 2 pieces - big!

[bpape]

The number of the prime has nothing to do with the frequency range. I can have either a 7, 11, 13, 17, etc. that can be low or high pending the width and depth.

Bryan

[srlaudio]

I have manufactured and listened to a broad array of diffusers, all varying in prime number and depth.  Recently I tried a new formula I had not used before, and the result was to my ears astounding.  It has a glow to the sound which is hard to describe but definitely desirable.  I know you will never achieve it with multiple small diffusers because I have tried.  Anyway, if you want something that kicks butt, here it is!  Here a picture on the loading dock....






Allen Rumbaugh