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OVERVIEW The section that follows presents the absorption data for all RealTraps products, plus products from a few other acoustic vendors. We also suggest you read the articles Measuring Absorption and Alternative Test Methods to understand how these products are tested, and why published values can be unreliable and are often inflated. Click HERE to see the fire and smoke testing data that earned MiniTraps their Class A fire rating. Although MicroTraps and MondoTraps were not tested, they are constructed identically so testing would show the same results. Note that to earn a Class A rating the Flame Spread Index must be under 25, and the Smoke Developed Index must be less than 450. (Products intended for plenum mounting require the Smoke Developed Index to be less than 50.) Click HERE to see photos of the tests performed at IBM's acoustics lab. |
Absorption
Comparison - values are Sabins per 4-foot unit (MondoTraps are 4'-9") |
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Absorption Comparison - values are Sabins per 4-foot unit (MondoTraps are 4'-9") |
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"One standard MiniTrap is nearly six times more effective than the same four-foot length of corner foam at 100 Hz and all lower frequencies."
"We're often asked how MiniTraps compare to various other products for which no data is offered."
"Would you buy an expensive pair of loudspeakers without having any idea of their frequency response?"
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TEST
DATA INTERPRETATION As you can see, one standard MiniTrap is nearly six times more effective than the same four-foot length of a popular brand of corner foam at 100 Hz and all lower frequencies. A MondoTrap absorbs twice again more below 100 Hz. Also observe that MicroTraps match or exceed the performance of 3-inch acoustic wedge foam panels above 160 Hz, even though MicroTraps are only one inch thick. Top It's important to point out that no US labs are certified to report absorption data below 100 Hz. This does not mean the data is suddenly useless below that frequency. Rather, the margin of error gradually increases so the absolute absorption figures can become less accurate. However, relative comparisons between different materials are absolutely valid, as long as the tests are performed on the same day in the same lab, and the materials are placed in exactly the same position in the reverb test chamber. Equally important is having a sufficiently large sample size - the ASTM recommends testing at least 60 square feet of material to obtain reliable data. So while the data below 100 Hz is not officially certified, it's a reasonably valid comparison and we include it here for completeness. All RealTraps products are tested at IBM's Hudson Valley Acoustics Laboratory in Poughkeepsie, NY. During testing the MiniTraps were mounted exactly as we recommend - in one test they were spaced four inches away from the mounting surface, and for the other they were placed in the room corners. Note that these tests yield absorption data as Sabins, which we converted to absorption coefficients using the standard method of dividing Sabins by the total square feet of front surface area. Both data formats are shown so you can easily compare MiniTraps to other products not listed here, regardless of how their performance is stated. Top Data for all but the two brands of corner foam was taken from the manufacturer's own literature. We are often asked how MiniTraps compare with corner foam but, sadly, the official test standards do not have a way to measure absorbers that are meant to be mounted in corners. So in order to obtain a fair comparison we hired IBM's acoustics lab to test eight 4-foot lengths of corner foam from Foam By Mail, and the same number of Auralex LENRD bass traps. These were placed in the same lab corner locations as MiniTraps when they were tested. What's most important here is the huge disparity in the first table (highlighted in white) between the data published by Foam By Mail versus what we actually measured in a real acoustics lab. To convert Sabins as measured to absorption coefficients we again used the standard formula that divides Sabins by the corner foam's front surface area of 5.67 square feet. (The 17-inch front width times four feet of length equals 5.67 square feet of front surface.) As with MiniTraps, the triangle shaped ends of each four-foot length of corner foam were exposed during testing, but not included in the calculation to convert Sabins to absorption coefficients. Top One of the ironies of acoustic testing is that every lab is different and gives different results, even for the exact same materials. Especially at low frequencies and especially when testing bass traps in corners. When our MiniTraps were tested in corners at this particular lab the absorption reported was three times higher than IBM's lab at 80 Hz, and fully twice as high at 100 Hz. For this reason it's important not to take such data too literally, or assume that one product is "better" than another based on published absorption data alone. However, labs are useful to weed out obvious fraud such as Foam By Mail. Much more information about the testing of absorbers is in RealTraps co-owner Ethan Winer's article Alternative Test Methods for Acoustic Treatment Products from Sound & Vibration magazine. One final point is the surprising number of acoustic product vendors who give no performance data at all. Testing in an acoustics lab is not free, but the cost is reasonable (about $1,000) for anyone running a real business. We're often asked how MiniTraps compare to various other products for which no data is offered at all. Think about that. Would you buy an expensive pair of loudspeakers without having any idea of their frequency response? Or a power amp with absolutely no distortion, noise, or even output power specs? Marketing acoustic panels without furnishing performance data tells consumers either "We have no idea if they actually work" or, worse, "We did test them and they're not very good." Top |
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