I got the go ahead to post this.
The test rig is a baltic birch box, with a pair of Hybrid Audio Technologies L6SE's bolted to one side, and an 12"x12" 16ga steel sheet clamped down around its outer half inch. This leaves an area of 11"x11" exposed. The back of the speakers are covered by a second box, to prevent any noise directly from the speakers from reaching the mic.
The mic is a Dayton Audio calibrated usb measurement microphone, and it is run through REW. All measurements are taken with sweeps in order to get both frequency response and decay plots. All measurements were taken with the panel at 77 degrees F, using an ir thermometer. All measurements include a bare metal measurements and a treated metal measurement. The treated metal measurement was taken with 28% coverage, and the test pieces of deadener were die cut to ensure consistency.
Products were also heat tested, and my summary includes my explanation in how that played into effect. Basically anything that had even a hint of risk of failing, got dinged. Anything that showed a history of failing or failed heat testing miserably flat out failed.
The margin of error on these tests is +/- 0.75db. I came to this conclusion doing multiple tests of several products, sometimes months apart.
I have no vested interest in any company. Some samples were provided by other car audio enthusists. Others were provided by sound deadening companies. There were company provided samples that did well and ones that did horrible.
This is the list of the majority of tested products and their results, in raw form.
http://www.diymobileaudio.com/forum/...-post1723.html
This is the results for Silent Coat products.
http://www.diymobileaudio.com/forum/...-post1724.html
And this is the final summary for the time being.
http://www.diymobileaudio.com/forum/...-post1725.html