Mathematically modeled sound attenuating / absorbing metamaterial.

[maxxevv]

Interesting possibilities with regards to room acoustics treatment in the future.

https://www.mnn.com/green-tech/rese...Ed-g7KIQnUeV-IIIwnukJnlvQbbVgRhpHJvS3rdK0-WRU

 

[pierre]

Associated paper can be found here: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.024302

 

[bigx5murf]

Would it make good speaker cabinet material?

 

[andreasmaaan]

Would it make good speaker cabinet material?

I suspect it would not be ideal as a cabinet material in its own right, as it would vibrate and potentially produce sound itself (although this is just a hunch based on its apparent weight and density - I can't find anything in the links discussing this).

Moreover (and I don't have access to the full article to confirm this) it seems that the material needs to be tuned to a specific frequency. It isn't a broadband absorber but rather a narrowband one that is extremely effective, but only in a very specific frequency range.

Perhaps if anyone has full text access they can confirm this?

 

[VMAT4]

From what I read it reflects sound back to the source.

 

[BillH]

Unfortunately the fractional bandwidth is only approximately 1/10 the center frequency. ( Fig 3)
Their demo is at 430 Hz but the attenuation is less than 100 Hz FWHM
On the flip side, the device dimensions are deeply subwavelength which makes it nice for low frequency resonance control from ducts and other mechanical systems.

 

[rocknss]

From what I read it reflects sound back to the source.

Correct

But the best part? The material not only strips the sound of the air, it sends it back where it came from.

I remember reading about acoustic diode years ago, this might be ideal for a listening room though haven't heard much on it in recent years.
https://www.popsci.com/science/arti...-travel-one-way-opens-door-true-soundproofing

 

[pozz]

I've contacted Acoustic Metamaterials Group in China previously, but they seem focused on industrial uses only.

 

[q3cpma]

What about active stuff like https://www.psiaudio.swiss/avaa-c20-active-bass-trap/ ? It's VERY expensive, though.

 

[RayDunzl]

From what I read it reflects sound back to the source.

Won't that burn out my speakers?

 

[Blumlein 88]

Won't that burn out my speakers?

Only if your amps are big enough. So in your case....yeah.

 

[Tks]

Someone call the MTA here in New York. Get these trains in these tubes, feel like I lost some of my hearing as a child going to school every day using the Subway..

 

[stevenswall]

They need to start selling these at standard vent sizes if they can be made to operate in the midband and treble... Put them in all of my vents to lower the sounds of voices and TV carrying to my room.

 

[pozz]

 

[maxxevv]

They need to start selling these at standard vent sizes if they can be made to operate in the midband and treble... Put them in all of my vents to lower the sounds of voices and TV carrying to my room.

It would be interesting if they can make them into door frames.

Where you can have sound isolation into and out of a room without actually having to seal it off. Like you can isolate the kitchen off from the living room and vice versa .... Would be pretty cool and neat if that comes to pass.

 

[stevenswall]

It would be interesting if they can make them into door frames.

The sound still has to hit the device I think to be affected. I wonder if the size of the opening increasing would make it unable to get rid of treble frequencies with small wavelengths?