Ethan Winer wrote on Sun, 01 February 2009 11:59 |
Note I'm addressing surface reflectivity only, not potential resonances from wood structures etc. |
Thomas Jouanjean wrote on Mon, 02 February 2009 08:26 |
You'd need measurements of a non-dampened or stiffened wood surface. |
Ethan Winer wrote on Sun, 01 February 2009 10:59 |
Note I'm addressing surface reflectivity only, not potential resonances from wood structures etc. |
PookyNMR wrote on Tue, 03 February 2009 19:00 |
Wouldn't the different resonance properties of the wood and it's attachment be a factor in the overall sound? |
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Is there a reason why a more holistic approach is not useful? |
andrebrito wrote on Thu, 05 February 2009 05:54 |
Using just Surface Ref. for this matter is a very simplistic approach |
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Sound absorption increases a lot in wood when sound is at higher angles of incidence |
andrebrito wrote on Thu, 05 February 2009 18:07 |
Am I allowed to attach a picture on this forum from a book from a public library ? About copyright issues... |
andrebrito wrote on Fri, 06 February 2009 05:54 |
From Acoustics of Wood book - pg. 22 - Voichita Bucur - Springer Editions Thanks for the explanation ! |
franman wrote on Fri, 06 February 2009 11:41 |
I knew that wood sounded warmer!!! |
andrebrito wrote on Fri, 06 February 2009 20:18 |
Can you imagine a guitar made of concrete !?! hahaha |
andrebrito wrote on Fri, 06 February 2009 06:54 |
From Acoustics of Wood book - pg. 22 - Voichita Bucur - Springer Editions |
Fig wrote on Fri, 06 February 2009 17:57 |
most musical instruments are made of the stuff. Must be a reason, right? |
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I've seen people argue that wood adds a pleasing quality to a room in the same way wood affects the tone of a fine violin. But that's a false analogy because the thin, resonant wood in a violin is meant to vibrate and add pleasing overtones. Versus wood on a floor or wall that is much thicker, and is anchored solidly to the wall or floor backing. Indeed, resonances in a musical instrument are desirable and necessary, but good listening rooms must aim to avoid all resonances as much as possible. |
Ethan Winer wrote on Sat, 07 February 2009 11:02 |
It seems unintuitive |
Thomas Jouanjean wrote on Tue, 17 February 2009 13:41 |
Everything about acoustics is [unintuitive] |
Ethan Winer wrote on Tue, 17 February 2009 16:28 | ||
It makes no sense that wood on a slab could absorb 80 to 90 percent around 1 KHz. The data I've seen is more like 6 percent. So this tells me the wood in that test was thin and suspended in the air. Or at least not mounted flat and bonded to cement as is done for floors, which is the intent of my article. --Ethan |
Thomas Jouanjean wrote on Wed, 18 February 2009 03:57 |
Ethan, the test was done in an impedance tube, like Andre said. So it can't be suspended in the air. But it's placed against something real hard and heavy (bottom of the tube) which implies high density, denser than cement. Don't confuse impedance tube test with reverb chamber tests. |
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The graph shows little absorption with perpendicular incidence. About what you mention, between 5 and 10%. If the piece of wood were to resonate (and surely it does on it's own) it would be best excited by a perpendicular incidence. |
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For your article to be worth any definitive conclusion, you'd have to measure in a reverb room with a parquet installed and without. |
Ethan Winer wrote on Wed, 18 February 2009 11:22 |
I don't know for sure either, but it seems that absorption would be maximum on axis and minimum when "grazing" edgewise. |
Ethan Winer wrote on Wed, 18 February 2009 11:22 |
The bottom line for me is that it makes no sense that a slab of wood bonded to solid cement can absorb 1 KHz by 80 to 90 percent at any angle! The huge drop in absorption around 3 KHz is also very telling, no? --Ethan |
Thomas Jouanjean wrote on Fri, 20 February 2009 03:13 |
don't draw fast conclusions based on partial data. |
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I would not rule it out though because it is likely a serious measurement. |
andrebrito wrote on Fri, 20 February 2009 14:24 |
I don't see how you can imply that. |
Ethan Winer wrote on Fri, 20 February 2009 13:20 |
but so far I'm not convinced there's anything wrong with my approach. |
Ethan Winer wrote on Fri, 20 February 2009 13:20 |
I don't understand way so many people, not just here but at Gearslutz too, want to cease the discussion of something that is so critically important to studio design. |
Ethan Winer wrote on Wed, 18 February 2009 11:22 |
The bottom line for me is that it makes no sense that a slab of wood bonded to solid cement can absorb 1 KHz by 80 to 90 percent at any angle! --Ethan |
Thomas Jouanjean wrote on Fri, 20 February 2009 18:27 |
Thread unlocked |
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The data you used in your article was for a very specific case, as a parquet of "over 10mm thickness" |
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I hope other contributors can come up with more infos! |
Ethan Winer wrote on Sat, 21 February 2009 12:42 |
Great, thanks. I didn't understand locking a thread where acousticians are discussing such an important acoustics issue. |
Ethan Winer wrote on Sat, 21 February 2009 12:42 |
All I did was find "Internet" data for various materials. I'm not so sure that > 10 mm is a standard thickness for parquet wood flooring. 10 mm is 0.4 inches, and the first link Google came up with is for tiles 0.31 inches thick (7 mm): |
Thomas Jouanjean wrote on Sat, 21 February 2009 14:31 |
I had a feeling this would go the GS way (running in circles leading to bickering etc). I will never allow this on this forum. |
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We just installed a 1.8cm thick beautiful oiled parquet in a studio, CR & LR. Darius @ Amsterdam Mastering did just the same too. |
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With the information we have, the answer leans toward a "Yes, but...", not the opposite. |
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Your article's conclusion: "Although some people believe that wood and cement and linoleum all sound different, any difference they heard is most likely due to other factors such as the size and shape of the rooms, and other surfaces present." Can you agree that this is not the right conclusion to give? It's rather misleading. |
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show at least that thickness matters a lot in how much of the "sound" you get. |
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You should as well at least mention and talk a bit about the re-emission factors |
Ethan Winer wrote on Sat, 21 February 2009 15:09 |
Was the wood on top of solid concrete? |
Ethan Winer wrote on Sat, 21 February 2009 15:09 |
"The information we have" is the crux of it. I give much more credibility to the data shown in my report than to the data in the book Andre posted. First, the data I used to calculate reflectivity agrees with most other data I've seen. It also agrees with what I consider common sense. |
Ethan Winer wrote on Sat, 21 February 2009 15:09 |
the data in that graph disagrees with all the other data I can find. |
Ethan Winer wrote on Sat, 21 February 2009 15:09 |
I cannot agree yet. Sorry! |
Ethan Winer wrote on Sat, 21 February 2009 15:09 |
That's a great idea. Do we have data for wood on cement at various thicknesses |
Ethan Winer wrote on Sat, 21 February 2009 15:09 |
Does re-emission happen with wood on cement, or only with wood on joists? Do we have any re-emission data? I agree that the more data we can see, the more complete the conclusion will be. |
franman wrote on Sun, 22 February 2009 12:04 |
Glenn, you got any spare popcorn??? |
Thomas Jouanjean wrote on Sat, 21 February 2009 17:48 |
You do realise that there is considerably more info on the subject in the article submitted by andre than in any of your supplied data? |
Ethan Winer wrote on Sun, 22 February 2009 13:23 |
Thomas, it would be great if you're able to measure this the next time you're about to install a wood floor over a concrete slab. |