Ethan: One of my concerns was the stability of the table used to support the speakers. I wonder if that impacted the results, especially in the bass region? Would a stack of concrete blocks performed better, or just differently, or would there be no change?
The vendors claim their isolators prevent speaker cabinet vibration from coupling to the surface they rest on, thus preventing that surface from resonating in sympathy. At least that's the claim made by those who claim anything at all beyond vague promises of better sound. So to test that claim we need a surface that can vibrate and ring, versus solid blocks.
JA: Have you any results checking the impulse response (or anything else) of the audio signal from your tests? Or were they solely focused on cabinet vibration?
The REW data file is on my web site, linked in the article. The article shows the impulse responses, and downloading the file lets people view and massage the data any way they like.
--Ethan