Can someone explain the tech behind the idea of building a subfloor filled with sand for the subs to sit on ? I have asked around no one knows. I have a decent background in audio and this is not making sense to me. My situation is as follows: I have 2 Adire Maelstroms, each in 11 cubic foot, ported (to Adire specs) downfiring enclosures. These sit behind a false front wall that holds the main speakers and the screen. Subs powered by QSC EX2500 (1500x1) As of now, the subs are sitting in the corner, on the concrete floor (theater is in the basement) Room is 12'x22'x7'10", full sound treatment in room. Bass is tight, low, clear, defined and quite loud. What gains if any would there be to have the subs sit on a wood floor filled with sand ? If anything, the concrete should help reinforce the bass, as the concrete will not resonate, nor should it absorb the frequencies. Any technical or practical explanation / experience would be appreciated.