Wolf, you must be kidding us. Under speakers you want either spikes or something that absorbs energy very well. That rubber is neither.
I use both Polycrystal spikes and Boston Audio tuneblocks for speakers with excellent results. Never tried anything else except stock spikes, that were junk.
I use both Polycrystal spikes and Boston Audio tuneblocks for speakers with excellent results. Never tried anything else except stock spikes, that were junk.