Pbowne: Correct, but totally off-base. You are right that 1-3 inches of space won't do anything to affect the transmission of low bass sound waves. Unfortunately, that's not the transmission that's in play here. What spikes help with is reduction of the transmission of vibrational energy from cabinet resonance due to a reduction in contact surface area between speaker cabinet and floor. Cabinet resonance isn't only caused by low frequency waves...any frequency can cause it. Which frequency does cause it in a particular speaker is determined solely by that speaker's cabinet design and construction.
To answer your question, the answer is no. Think of it this way...your ear canal/eardrum is only about 3/8ths of an inch across, does that mean we can't hear any frequency with a wavelength longer than that? Low frequency waves, as you correctly point out, have huge wavelengths. Unlike higher frequency waves, these suckers don't care about walls, or even our heads and simply pass right through. You will still hear them just fine, provided they are still in the audible range, that is. It is standing waves that are affected by room size, not sound waves coming directly from the speaker. Hope that helps...
