Cut 'em in quarters/4's...buy two pot holders and you'll have 8 in total.
Snip a square of aluminum foil the same size as the squares and glue down between two silicone squares. You've now just added to the energy dispersion characteristics by adding a constrained layer (the aluminum foil in the middle helps dissipate energy into heat). Snip 8 squares of aluminum foil in total and you'll have enough for the two small speakers.
I've used this under a variety of components in the past, and it's cheap and quite effective. But, I still find the purpose built puds from LAT International called 'Vibra Killers' to be more effective, overall.
http://www.latinternational.com/index.php/product/vibra-killers.htmlOf course it's $39.90 versus maybe $10.00 and a bit of time for the 2 pot holders and a teeny bit of Reynolds Wrap. I'm partial to the red potholders, myself...but the blue ones are purdy, too