Hi.. I heard of how the half-square thing improves sound quality when put under the foot of CD players, amp, and speakers. It absorb vibration. But I disagree about putting them under speakers foot. Why should absorb vibration from speakers? Those speakers need stability, the reason why stands and spikes are used. If the rubber is put under speakers, it absorb vibration and reduce ability to shift air, moves speaker box behind against its driver, and reduce bass.