Sound suppressing fabric

[AusTex64]

I was quite skeptical until I read the paper.

https://news.mit.edu/2024/sound-sup...te-quiet-spaces-0507?utm_placement=newsletter

 

[SubSpec]

researchers found that holding the fabric still causes sound to be reflected by the fabric

I assume that this means making it still by producing (for lack of a better term) phase reversed vibrations across it rather than simply stretching it to the point that minimizes vibrations (to the extent that is even possible). Some of the wording is ambiguous about whether the second approach is active or passive, but I have to assume it is active like the first. Though a boy can dream...

Edit: Re-reading makes it clear both approaches are actively vibrating the fabric.

 

[Whoops]

I was quite skeptical until I read the paper.

https://news.mit.edu/2024/sound-sup...te-quiet-spaces-0507?utm_placement=newsletter

I’m still highly skeptical

 

[cyrano]

I've seen far too many press releases like that. Remember when the glass industry was pushing sound isolating glass? And IR radiating glass? And glass that had switchable transparency?

All inventions that were touted decades ago. You'll have a hard time buying them today, as none were as successful as their press release predicted.

 

[JohnRoberts]

I feel like we've seen this before but I can't find an earlier thread.
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+1 not likely to be practical.

JR

 

[AusTex64]

MIT is a very reputable joint I hear. And the research was funded by some heavy hitters:

<This work is funded, in part, by the National Science Foundation (NSF), the Army Research Office (ARO), the Defense Threat Reduction Agency (DTRA), and the Wisconsin Alumni Research Foundation.>

If I read this correctly, they claim 65db suppression from 200Hz to 5000Hz: https://onlinelibrary.wiley.com/doi/full/10.1002/adma.202313328

 

[JohnRoberts]

MIT is a very reputable joint I hear. And the research was funded by some heavy hitters:

<This work is funded, in part, by the National Science Foundation (NSF), the Army Research Office (ARO), the Defense Threat Reduction Agency (DTRA), and the Wisconsin Alumni Research Foundation.>

If I read this correctly, they claim 65db suppression from 200Hz to 5000Hz: https://onlinelibrary.wiley.com/doi/full/10.1002/adma.202313328

Yup my older brother got his Phd there, me I only worked there (in the Instrumentation lab).
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IIRC this invention cancels noise by generating a opposing waveform with a piezo fabric... This takes energy and sophisticated control. As often happens they are overselling this cute puppy making impractical claims for it.

JR

 

[samplebias2]

I have a huge rug on one wall, some 2x4 pyramid foam panels in my room to reduce that stucco "slap" when I record VO. Wish there was a cheap, aesthetic magic bullet for this.

 

[JohnRoberts]

I have a huge rug on one wall, some 2x4 pyramid foam panels in my room to reduce that stucco "slap" when I record VO. Wish there was a cheap, aesthetic magic bullet for this.

A rug sounds like a pretty cheap treatment. There is an entire industry dealing with recording studio and control room acoustic management.

JR

 

[kags]

Roxul safe n sound (or similar 4” mineral wool) wrapped in fabric with 2x4 framing and your own labor is about $1.50 per square foot - can’t get much cheaper. Plus all the supplies are easy to source.

 

[RoadrunnerOZ]

Add to that a mass loaded vinyl backing and you’d be pretty good.
(It seems if the piezo sound wave generator fabric had alternate lines of piezo fibre to receive the external noise source, if it works as an electrical generator, and generate a signal, which could then be phase inverted and amplified, sent into the transmission fibres to actively cancel it could be even more effective - but you’ll probably need two layers, porous to receive and much less porous to transmit - situated behind the receiver fabric).
Using crossweave would allow localised control but this would entail lots of amplification channels both to receive and transmit.

The concept is a good idea in theory except for one thing and that is where the reflected sound goes. In a free standing area like a privacy screen in a hospital it’d be ok but for recording studio applications it might introduce an even bigger set of problems.

 

[RoadrunnerOZ]

I've seen far too many press releases like that. Remember when the glass industry was pushing sound isolating glass? And IR radiating glass? And glass that had switchable transparency?

All inventions that were touted decades ago. You'll have a hard time buying them today, as none were as successful as their press release predicted.

I have used vacuum insulated double glass panels for door windows in studios I’ve built before - one instance was sliding solid acoustic doors between two live rooms, total of 6, about 25mm thick panels made to size - that glass works really well.

 

[Gold]

Northward Acoustics uses glass front walls in some of his control room designs. It works very well but he knows what he is doing. I would not attempt a DIY glass front wall.

 

[RoadrunnerOZ]

I’ve designed & been involved in building over 30 studios - some small and some large - and in some I’ve had really large glass window frontage into live rooms using triple glazing 12/8/12mm or 8/6/8mm reinforced, angled and rubber strip base mounted with neoprene seal strips on timber sill/surrounds abutting each pane, front and rear full 360° surround with split frames also mastic filled gapping and hidden water absorption trays. The abutting outer and inner locking framework which holds the glass in place is also removable to allow for pane replacement in case of breakage or to allow cleaning. Each pane had to be cleaned 3 times before installing using lint-free cloths and paper and special window cleaner spray - hell of a job with the thick outer panes, doing a final wipe with them sitting on the frame isolator strip leaning out - they’re heavy!! One I did back in 1991:
https://www.facebook.com/rockinghorsestudiosbyronbay/
Triple glazed control room to live room with another triple glazed set in direct line from the live room to look out over the valley through the live room from the control room, plus from control room into smaller live/guitar room and on through tall glazing in sliding heavy doors into another live room/lounge area.
I can’t imagine the immense weight of a full glass front and the difficulty in installation for double or triple glazed but I guess not too much different to shopfront windows or granite and marble walls - you just need the right gear and people.

 

[JohnRoberts]

Yup, console control room glass typically used multiple air spaces, and angled panes to reduce coupling.

You could use the sound suppressing fabric to make a curtain.

JR

 

[RoadrunnerOZ]

Yeah - instead of heavy isolating gobo panels on wheels or stands just a lightweight frame with the fabric stretched on it

 

[RoadrunnerOZ]

If you could use a clear synthetic fibre you could make mobile drum booths with view panels

 

[Gold]

Northward uses glass as the complete front wall , including soffits. The speakers are suspended under tuned tension in the glass wall via aircraft cable. Very slick.