OK, so if they are 45PSI rated, and there is 81 of them per sheet, do you really need the whole sheet or do you cut away individuals and bond (using double sides tape) one per corner of the speaker?I had a feeling you'd ask...
I've had a hard time finding any place in the US that sells it... I think it's rarely purchased by individuals..
I found this:
And that's $86 for an 18" x 18" square. Seems rather pricey. Hmmm.. $72 here, http://www.grainger.com/Grainger/MASON-Neoprene-Mounting-Anti-Vibration-Pad-4C972
70-80 seems expensive for 4.5 lbs of rubber.
I will go down to a local rubber supplier later today and ask and them for a price on their similar rated rubber mats and we shall see what they have and what they want for it. I just have to remember not to mention HT or it goes up 3x anyway. The mere mention of HT in this country seems to be as bad as the word "wedding".