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Originally Posted by Ethan Winer Jeff,
> Did you have your stuff tested at Riverbank recently? If so, why the switch? They're both reputable labs. <
We have not retested any of our products lately, and I was referring to the data you measured when you worked for Auralex. But we have considered either measuring our traps again at Riverbank, or buying some of Glenn's panels (and maybe some other vendors too) and testing them at IBM. As you know, corner testing can create more questions than answers when different labs are used. Not only different labs, but different places within each lab. I know where MiniTraps were placed in the IBM lab's corners and I have detailed photos of every test session. But I don't know where all of Glenn's panels were placed in Riverbank's lab. Maybe his were closer to tri-corners than ours were or vice versa, or maybe the labs are different sizes and shapes? Based on the photos at GIK's web site even for the "A" mounting tests it looks like the traps were not placed in the center of the room where they should be. Or maybe those are the "J" tests? Who knows, since it's not explained anywhere.
As you yourself pointed out months ago elsewhere, it's not fair or ethical to compare corner tests in different labs because of these variables. Indeed, when I compare the data you measured for MiniTraps at Riverbank with Glenn's 4-inch and 7-inch panels also measured at Riverbank, MiniTraps beat Glenn's 4-inch panels by 3 to 1 at 63 Hz, and they beat Glenn's 7-inch panels by 2 to 1 there. Since MondoTraps absorb twice as much as MiniTraps at 100 Hz and below you can extrapolate from that.
Does this mean that based on the Riverbank data, MondoTraps beat Glenn's 7-inch panel by 4 to 1 at 63 Hz? Maybe, maybe not. You didn't test enough MiniTraps to get certifiable data, and I don't know where in Riverbank's lab any of the traps were placed for any of those tests. I do know that you put the MiniTraps adjacent, and that reduced their absorption compared to having them spaced apart as we recommend. So maybe MiniTraps would have measured an even larger advantage had they been spaced a few feet apart. This is the real issue: The only way to compare two products fairly and ethically is to measure eight of each, and do all tests in the same lab in the same locations. Anything else is just guessing.
All of this is aside from the reality that lab measurements vary wildly even when performing standard ASTM C-423 tests. Especially at 125 Hz and below. Based on the data I've seen it's clear that Riverbank reports on the high side, at least when compared to IBM. Is Riverbank high? Or is IBM low? Or maybe both? Who knows!
There's also a lot more to assess than just raw Sabins of absorption. The balance of absorption versus frequency is important (and is a very big feature of all RealTraps), as is fit and finish, product durability, ease of installation, expertise of product support, and on and on.
--Ethan |
?????? If you go to our site you can down load the PDF's of the lab reports.. I know you are a smart guy so you do understanding "A" testing. Unlike a few companies, we take a lot of pride in showing all reports and not hiding behind HTML or only showing sabins when is works in our favor..
Not sure how this whole comparing thing started, but as you have stated to me our product is for the bottom feeder and your is for the pro.. As we do not look at our customers as bottom feeds, but people who can not or will not spend lots of money on acoustics.. I think it is safe to say that we have done pretty well in having a product that is tested and proven.. You Ethan have the same and look to you to grow awareness of acoustics with your background.. I guess what I am trying to say is get off my back..
Please everyone understand that I really have the highest respect for Ethan and his product...
Glenn