[quote name='alexclaber' post='506429' date='Jun 5 2009, 03:39 PM']Unfortunately it's the rather random and unpredictable variety of coupling called mechanical coupling, whereby the stage floor acts as a giant drum skin. I wouldn't want to be reliant on that for my lows, especially as it often causes big bottom onstage but not out in the room where you really need it.
To get acoustic coupling just keep your cab within a foot or two of the floor and walls - that gives you extra lows with little risk of membrane resonance weirdness, just straightforward reflected sound from your cab coming back and reinforcing the sound that's going forward.
Alex[/quote]
Ta. Keeping my cab a foot of the floor will be in interesting challenge--moving it horizontally is hard enough!