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Post by Hexspa on Jun 14, 2017 21:14:55 GMT
New Sound Diffuser Is 10 Times Thinner Than Existing DesignsOfficial Paper - Ultra-thin Acoustic Metasurface-Based Schroeder DiffuserFound on Reddit. More reading claiming unoriginality of the design (despite mention within the paper). Someone makes an interesting point regarding the reflectivity beyond the diffusers maximum effectiveness basically saying, "why not put a thin absorber in front to combat that?" Despite that clearly not being diffusion, that solution could have it's place. "...fully functional prototypes using a 3-D printer..." Seems legit. I'm not supposed to mention "other acoustics companies" but one of em seems to be falling over themselves in the comments in that first link. I would feel tempted to research 3-D printers if a modular blueprint could be made available unless they'd be priced proportionally to their smaller size (ya right). Apparently, they've performed tests from 5772-8153Hz at least. I don't see anything below that, measured or simulated. As a side note, we haven't talked much about pure diffusion being a viable solution in a small room. Hypothetically, with either this or previously existing technology, and basic practicality aside, would pure diffusion be a legitimate strategy for treating a small room? -m
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Post by Hexspa on Jun 15, 2017 0:54:58 GMT
Seems like this Schroeder guy is pretty important in the Acoustics world.
One thing I've noticed is that, when using the AMROC calculator to determine my "Schroeder Frequency", I generally have a null at that cutoff. I think this has been true of my current and previous rooms.
Does anyone know what happens there? Is it like a "sonic boom"? My understanding of the S.F. is that, below it, your room acts like a bottle when it's blown into; it has certain resonances. Above the S.F., you have freely-moving waves which will act more like you'd expect to treat with RFZ panels. That might be totally wack but it's been working for me so far. Anyway, if there's a point then something changes. Is it supposed to be a fluid change or is there some kind of conflict between the two sides of it?
I didn't realized that Schroeder is the developer of the QRD.
Thanks, University of Google!
-m
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Post by Ethan Winer on Jun 19, 2017 17:45:24 GMT
Peter Janis is a good guy, but I agree with him. Without proof it's just a bunch of marketing blather.
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Post by Hexspa on Jun 19, 2017 18:37:37 GMT
Peter Janis is a good guy, but I agree with him. Without proof it's just a bunch of marketing blather. Would you consider a research paper like this marketing? I guess if the motivations are suspect i.e. promoting one's own research career. Commercial options aren't available from what I gather. There is proof in that paper, like I mentioned. Just wondering. Thanks, -m |
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Post by Ethan Winer on Jun 22, 2017 19:16:59 GMT
Research paper? Did I miss the performance data?
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Post by Hexspa on Jun 23, 2017 0:37:54 GMT
Research paper? Did I miss the performance data? There's a whole lot of numbers not understood by this mind but the pictures and gist of text seem to indicate both simulated and measured results including comparisons to regular a Schroeder diffuser in terms of phase shift, diffusive effect and broadband performance. |
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Post by Ethan Winer on Jun 27, 2017 19:16:53 GMT
I'm not a math guy so that stuff was lost on me too.
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Post by cyclecamper on Jul 24, 2017 1:37:29 GMT
I believe I saw this. At first look, I would expect much of the flat surface to be rather ineffective at very high frequencies but trade that for better performance (for its limited depth) in a lower band. We're always talking about how the depth of a diffusor dictates how low it will work. Well, here's how to make one that, when space for depth is limited, will work lower but not as high, which is more useful than a miniature conventional diffusor. I have no idea how effective. I could imagine virtues of each type in different locations.
If this was an absorber rather than a diffusor certainly that face panel shape with cutouts would pass lows to be absorbed behind but reflect highs; looks like a first-order acoustical low-pass face panel to me.
What comes back out with various delays as a diffusor and how those delays interact...I will just assume they did the math right LOL.
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Post by Hexspa on Nov 17, 2017 3:55:13 GMT
I believe I saw this. At first look, I would expect much of the flat surface to be rather ineffective at very high frequencies but trade that for better performance (for its limited depth) in a lower band. We're always talking about how the depth of a diffusor dictates how low it will work. Well, here's how to make one that, when space for depth is limited, will work lower but not as high, which is more useful than a miniature conventional diffusor. I have no idea how effective. I could imagine virtues of each type in different locations. If this was an absorber rather than a diffusor certainly that face panel shape with cutouts would pass lows to be absorbed behind but reflect highs; looks like a first-order acoustical low-pass face panel to me. What comes back out with various delays as a diffusor and how those delays interact...I will just assume they did the math right LOL. That's an interesting point, cyclecamper. I, too, wonder how the highest frequencies would perform with so much flat surface. Despite flat surface being present in this design, it's also present in current Schroeder diffusers. I'm coming back to this thread to see if anyone is planning to implement a commercial version of this. It seems like someone with a 3D printer could just treat their entire room with such a design. |
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