Magnetite Windows
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vince.cimo
- Posts: 19
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- Location: San Luis Obispo, CA
Magnetite Windows
Anyone ever try these out? They claim to almost double the STC rating of existing windows. http://www.magnetite.com/
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Soundman2020
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Re: Magnetite Windows
Hi. Please read the forum rules for posting (click here). You seem to be missing a couple of things! 
From the minimal technical data on that web site, I'd be rather skeptical that it would be any use in a studio... The explanation given there for STC is wildly inaccurate, for example (there is no direct relationship between STC numbers and decibels of transmission loss), and there's no independent laboratory test results shown for the products, which is always a red flag for acoustic products. Even though they claim that their products have been tested in independent labs, I could not find the results of those tests published on their web site. You might want to call them and ask them to send you a copy of the full set of test results for those windows. Maybe they actually will send it to you....
Another red flag is referring to sound reduction in terms of percentage: It sounds good to say that a product "reduces sound by 70%", but that is basically meaningless. Is that a 70% reduction in sound power, sound pressure, sound intensity, perceived sound level, or some other measurement? In the professional acoustics world, sound reduction is always stated in decibels, never percentage, and is almost always given with respect to a reference level, usually with a weighting curve too, where applicable. Which makes sense when you realize that, in reality, reducing the intensity of a sound by 70% means that the level dropped by just a bit more than 5 decibels... Not exactly earth-shattering news!
In reality, there is no such things as "soundproofing" as a technical term. "Sound isolation" and "transmission loss" and "sound reduction" are some of the technical terms used to refer to what laymen (and also snake-oil salesmen among others) call "soundproofing".
There's also the misleading claim that the product is made from the "same window material found in Jet Aircraft - It's called "Optical Grade Acrylic". Well yipeee. Wonderful. I have some plates and coffee mugs made from the same stuff, but I wouldn't make any claims for them about how soundproof they might be... The reason why windows in aircraft work so well is because they are designed as a system of several parts, not just a single sheet of plastic...
In reality, sound isolation requires a properly designed system, not just a magical product. I'm sure that the claims they make for their product "reducing sound by 70%" are true, since there are a couple of ways that one could accomplish that in a carefully designed "test". I'm also sure that they did actually conduct one test where the STC rating of a window system went up in the manner they claim. But that does not mean that you would get results even vaguely similar to that claim, since your system is very likely a whole lot different from their system It is quite possible that using that product (or any other similar product) on an existing 2-leaf window could actually reduce the "soundproofing" of the window at low frequencies, not increase it. It all depends on how the existing window is constructed, how the new panel was added to it, and how the test was conducted.
They do mention that they tested the windows "according to ASTM-E90", but the notes on the ASTM-E90 test procedure state: "... sound ratings obtained using this test method do not relate directly to sound isolation in buildings; they represent an upper limit to what would be measured in a field test.". Hmmm....
So I'd suggest taking those claims with a large grain of salt, unless they actually do send you the independent laboratory reports that demonstrate that the claims are 100% accurate and correct.
- Stuart -
From the minimal technical data on that web site, I'd be rather skeptical that it would be any use in a studio... The explanation given there for STC is wildly inaccurate, for example (there is no direct relationship between STC numbers and decibels of transmission loss), and there's no independent laboratory test results shown for the products, which is always a red flag for acoustic products. Even though they claim that their products have been tested in independent labs, I could not find the results of those tests published on their web site. You might want to call them and ask them to send you a copy of the full set of test results for those windows. Maybe they actually will send it to you....
Another red flag is referring to sound reduction in terms of percentage: It sounds good to say that a product "reduces sound by 70%", but that is basically meaningless. Is that a 70% reduction in sound power, sound pressure, sound intensity, perceived sound level, or some other measurement? In the professional acoustics world, sound reduction is always stated in decibels, never percentage, and is almost always given with respect to a reference level, usually with a weighting curve too, where applicable. Which makes sense when you realize that, in reality, reducing the intensity of a sound by 70% means that the level dropped by just a bit more than 5 decibels... Not exactly earth-shattering news!
In reality, there is no such things as "soundproofing" as a technical term. "Sound isolation" and "transmission loss" and "sound reduction" are some of the technical terms used to refer to what laymen (and also snake-oil salesmen among others) call "soundproofing".
There's also the misleading claim that the product is made from the "same window material found in Jet Aircraft - It's called "Optical Grade Acrylic". Well yipeee. Wonderful. I have some plates and coffee mugs made from the same stuff, but I wouldn't make any claims for them about how soundproof they might be...
The reason why windows in aircraft work so well is because they are designed as a system of several parts, not just a single sheet of plastic...In reality, sound isolation requires a properly designed system, not just a magical product. I'm sure that the claims they make for their product "reducing sound by 70%" are true, since there are a couple of ways that one could accomplish that in a carefully designed "test". I'm also sure that they did actually conduct one test where the STC rating of a window system went up in the manner they claim. But that does not mean that you would get results even vaguely similar to that claim, since your system is very likely a whole lot different from their system It is quite possible that using that product (or any other similar product) on an existing 2-leaf window could actually reduce the "soundproofing" of the window at low frequencies, not increase it. It all depends on how the existing window is constructed, how the new panel was added to it, and how the test was conducted.
They do mention that they tested the windows "according to ASTM-E90", but the notes on the ASTM-E90 test procedure state: "... sound ratings obtained using this test method do not relate directly to sound isolation in buildings; they represent an upper limit to what would be measured in a field test.". Hmmm....
So I'd suggest taking those claims with a large grain of salt, unless they actually do send you the independent laboratory reports that demonstrate that the claims are 100% accurate and correct.
- Stuart -