The argument for/against room treatment

[Cellcbern]

Do you have any acoustic measurements to substantiate such claims?

Do you have any acoustic measurements to substantiate such claims?

I don't do measurements. I trust my ears. Which claims?

 

[Cellcbern]

Wow, that must have taken the marketing guys a while to think up.

By the way, from your photos, your room looks way over damped (too much treatment). Did you have someone treat the room or do it yourself?

Did it myself. Not over damped at all. As I've said - best sound I've ever achieved.

 

[Solypsa]

Always hate it when 'quantum anything' gets added to a products marketing, however I am not a scientist nor have I heard what these ZR panels do so no comment directed towards them. I am a little confused at the difference between 'zero reflection' and 'anechoic'...

 

[cal3713]

Diffusors scatter the sound waves and have to be tailored and targeted to specific frequency ranges and room dimmensions. ZR Acoustics panels prevent reflected sound waves from forming ( at a molecular level according to DHDI) by bouncing the air off of many thousands of non-parallel surfaces per square foot of panel, and work at all frequencies.

I'm not trying to be difficult, but this still reads like an explanation of diffusion. Diffusers scatter sound waves (which are necessarily transmitted by air in our listening environments) by bouncing air off of a corrugated surface. There are many different patterns that can be used to accomplish this effect, each of which change the frequencies that are influenced.

Perhaps this product has created a novel corrugated pattern that increases the effective frequency range?

 

[pjwd]

I'm not trying to be difficult, but this still reads like an explanation of diffusion. Diffusers scatter sound waves (which are necessarily transmitted by air in our listening environments) by bouncing air off of a corrugated surface. There are many different patterns that can be used to accomplish this effect, each of which change the frequencies that are influenced.

Perhaps this product has created a novel corrugated pattern that increases the effective frequency range?

Yes I am pretty sure low fr waves haven't read the theory and would just see a flat wall ... it seems primarily a diffuser for HF but it may have an interesting sideways dispersion and perhaps some cancelling nulls in that dispersion ( partcularly at centre of circles) that lowers reflections back to the listener without greatly reducing the "life" in the room. Its pretty hard to visualize what might happen in that circular pattern .. you see a few products like that but no one publishes dispersion patterns as far as I know
It clearly does something clever as folks like them but I agree the marketing blurb seems bonkers
Phil

 

[Cellcbern]

I'm not trying to be difficult, but this still reads like an explanation of diffusion. Diffusers scatter sound waves (which are necessarily transmitted by air in our listening environments) by bouncing air off of a corrugated surface. There are many different patterns that can be used to accomplish this effect, each of which change the frequencies that are influenced.

Perhaps this product has created a novel corrugated pattern that increases the effective frequency range?

The trade secret, what makes ZR Acoustics panels work as claimed is a precise, specific size, angle, and pattern of non-parallel surfaces. Hanson Hsu was granted U.S. Patent #9,845,598 for the original Zero Reflection panel design. The current circular one that they use (as in my photos) is an advancement on and superceded that original design.

 

[DaveC]

One thing to avoid at all costs is having the LP right up against the back wall.

 

[Cellcbern]

One thing to avoid at all costs is having the LP right up against the back wall.

One thing to avoid at all costs is having the LP right up against the back wall.

Ideally yes but not always possible in a small room, and moving the listening seat a few feet from the rear wall doesn't make much difference. With the ZR Acoustics panels the best sound in my room is with the listening seat up against the rear wall/panels as in the "Creator Series" example at the DHDI website :

https://deltahdesign.com/wp-content/uploads/2015/01/zr-davincerear.jpg

 

[microstrip]

ZR Acoustics panels prevent reflected sound waves from forming ( at a molecular level according to DHDI) by bouncing the air off of many thousands of non-parallel surfaces per square foot of panel, and work at all frequencies.

I don't do measurements. I trust my ears. Which claims?

Those that are quoted in your post. One thing is telling us about your room, endorsing the manufacturer claims needs something to substantiate them.

 

[microstrip]

Always hate it when 'quantum anything' gets added to a products marketing, however I am not a scientist nor have I heard what these ZR panels do so no comment directed towards them. I am a little confused at the difference between 'zero reflection' and 'anechoic'...

Yes, the quantum verbose looks like pure marketing. The manufacturer wisely avoided the word quantum in the patent that protects the design of the panel - the patent board would immediately refuse it if it included such abusive claims.

BTW patents just protect an invention, nothing else. There was no science in the paperclip invention!

 

[cal3713]

Anyone have access to this journal via work?

I'm curious how thick they have to get to get down to 225hz.

Broadband fractal acoustic metamaterials for low-frequency sound attenuation: https://aip.scitation.org/doi/10.1063/1.4963347

 

[Cellcbern]

Those that are quoted in your post. One thing is telling us about your room, endorsing the manufacturer claims needs something to substantiate them.

I think the client lists speaks to the efficacy of the product: https://deltahdesign.com/portfolio/

DHDI is not sharing their trade secrets.

I've described my experiences with the ZR panels based on what I hear. That's all I have to offer.

 

[Cellcbern]

Anyone have access to this journal via work?

I'm curious how thick they have to get to get down to 225hz.

Broadband fractal acoustic metamaterials for low-frequency sound attenuation: https://aip.scitation.org/doi/10.1063/1.4963347

Panel thickness/depth is irrelevant to the ZR technology since the panels don't absorb, diffuse, or trap. You can see in the comparison/price list what the thickness of the various panels is:

https://deltahdesign.com/wp-content/uploads/2015/01/21-0601-ProductCompSht-UPP.pdf

 

[cal3713]

Here's another product that also uses fractal patterns to accomplish broadband diffusion. I sat right up against the rear wall with a SD9F panel behind me @ Aaudio Imports when he was in Colorado and could not hear any reflected sound. It was very impressive.

https://www.goldenacoustics.com/productsLine.php

That panel goes down to 70Hz, but is quite a bit bigger than the ZR panels... Depth: 9in, Length: 94in, Width: 34in, Weight: 150lbs.

 

[Kal Rubinson]

Here's another product that also uses fractal patterns to accomplish broadband diffusion. I sat right up against the rear wall with a SD9F panel behind me @ Aaudio Imports when he was in Colorado and could not hear any reflected sound. It was very impressive.

https://www.goldenacoustics.com/productsLine.php

That panel goes down to 70Hz, but is quite a bit bigger than the ZR panels...

but much uglier.

 

[the sound of Tao]

Here's another product that also uses fractal patterns to accomplish broadband diffusion. I sat right up against the rear wall with a SD9F panel behind me @ Aaudio Imports when he was in Colorado and could not hear any reflected sound. It was very impressive.

https://www.goldenacoustics.com/productsLine.php

That panel goes down to 70Hz, but is quite a bit bigger than the ZR panels... Depth: 9in, Length: 94in, Width: 34in, Weight: 150lbs.


View attachment 80009

I love the sense of invention in our hobby and our commitment to sound above all things Cal… but this does rather look like Dolly Parton’s sound recording studio.

So just what is the male equivalent of Waf… uhmmm may I suggest that the mother of pearl finish here in particular has rather low Maf… or is it Haf

 

[dcathro]

I love the sense of invention in our hobby and our commitment to sound above all things Cal… but this does rather look like Dolly Parton’s sound recording studio.

So just what is the male equivalent of Waf… uhmmm may I suggest that the mother of pearl finish here in particular has rather low Maf… or is it Haf

I don't know, it could double as a climbing wall

 

[the sound of Tao]

I don't know, it could double as a climbing wall

Dolly Parton?

 

[pjwd]

Here's another product that also uses fractal patterns to accomplish broadband diffusion. I sat right up against the rear wall with a SD9F panel behind me @ Aaudio Imports when he was in Colorado and could not hear any reflected sound. It was very impressive.

https://www.goldenacoustics.com/productsLine.php

That panel goes down to 70Hz, but is quite a bit bigger than the ZR panels... Depth: 9in, Length: 94in, Width: 34in, Weight: 150lbs.


View attachment 80009

You can see the logic in that one ... the relections are up and down from ear level and the diffuser depth at ear level could work at 70Hz
Dont know what the patterns down each side do but at least the whole unit is non symmetric minimizing lobing between like dispersion patterns from each panel .. as you go higher and lower they reflect back into the room rather than up and down , avoiding ceiling relections back to listener
I see on their site they also have an option cover them with a stretch fabric ... even they understand they are butt ugly as Kal notes below!

 

[cal3713]

You can see the logic in that one ... the relections are up and down from ear level and the diffuser depth at ear level could work at 70Hz
Dont know what the patterns down each side do but at least the whole unit is non symmetric minimizing lobing between like dispersion patterns from each panel .. as you go higher and lower they reflect back into the room rather than up and down , avoiding ceiling relections back to listener
I see on their site they also have an option cover them with a stretch fabric ... even they understand they are butt ugly as Kal notes below!

Different patterns for different frequencies...

Here's their marketing spin:

"Fractals are objects, which have scalable, repeatable properties. So, the unique form, that our distribution panels are based on, is an organically derived, balanced fractal based on a triad of the golden section. The sizing of these Golden Section fractals are such that each size has a specific frequency range, proportioned using a Fibonacci sequence, so that they distribute full spectrum sound waves. The fractals are then positioned and rotated, in relationship to one another creating an array. This is done to utilize one of nature's most profound ratios to reflect the full audio spectrum in the most efficient manner possible. Our broadband, sonic distribution panels, depending on their method of installation, help to equalize the full audio spectrum, from 20 Hz to the upper limit of hearing, 20kHz.

All our products are able to be back-filled with sound absorbing material. This can be done with mineral wool, fiberglass or poly-foam. This allows for an inexpensive method to control reverberation times for any given space."