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Post by rock on Sept 14, 2016 12:00:40 GMT
Hi Wei,
It is the density. BUT with a depth of 24", the density is not that important either. The fact you are making the absorbing wall so thick (deep) minimizes the need for higher density material because you have so much volume if insulation. So don't worry too much about the density, I suggest you buy the cheapest per unit volume.
Now, just as another example in the opposite direction, if you had a much thinner absorber of only 2", the higher density would make more of a difference. After 8" thick, the lower density works OK.
Cheers,
Rock
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Post by Hexspa on Sept 15, 2016 10:37:21 GMT
Ethan proved that 703 will work in thicknesses above 1".
"Eight inches and thinner - rigid's the winner. Deeper than that, pink is the champ."
That's the rule of thumb which encapsulates all the variables of R value, density, thickness and gas flow resistivity.
Beyond that I reckon you're learning for the sake of curiosity and will pay with the currency of time.
-m
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Post by rock on Sept 15, 2016 11:12:34 GMT
Yes, from my observation, they are related but the greater the depth, the less all that matters. To repeat, for 24" thick absorber, buy the cheapest fluffy per unit volume.
Cheers,
Rock
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Post by Hexspa on Sept 16, 2016 3:46:46 GMT
Ethan proved that 703 will work in thicknesses above 1". "Eight inches and thinner - rigid's the winner. Deeper than that, pink is the champ." That's the rule of thumb which encapsulates all the variables of R value, density, thickness and gas flow resistivity. Beyond that I reckon you're learning for the sake of curiosity and will pay with the currency of time. -m Hi M, I think you might type wrong about the 1'' : ) No, pretty sure I didn't. 1" 703 isn't good for bass but, the greater the thickness (up to 8") you'll get better effect - particularly with an air gap. I've got measurements to back it up. You can download my book which gives REW examples of before and after measurements of my current room. I'm using 8lb mineral wool in a 2(2") format which is a 703 analog. Yes, I'm also using fluffy super chunks but if I were to replace the material with mineral wool I'd probably get even better results. hexspa.com/listening-room-ebook - free. But if you know something that none of us do please share. Thanks, -m EDIT: I think I understand what you're saying. What I'm hearing you say is that you think I mean one can use anything less than 8" of rigid material and get the same result as thick fluffy. That's not what I meant. I meant that in applications where you'll be using treatment appropriately, 8" is the cutoff point between the right usage of each respective material. So, for example, if you just want to control ambience in an open loft-type or gym space then you might get away with using 1" rigid panels. The more music-related you get (and other variables) you want thicker insulation while placing somewhat less emphasis on density. But I still think my cute rhyme is more elegant than saying all that *hehe*. |
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