The other issue is how the resulting impulse response is affected by the
walls of the room rapidly accelerating away from the microphones.  Expanding
universe-like doppler shift.  Which brings up the use of extremely dense
matter, to both generate the impulse and balance the forces that are causing
the walls to accelerate.
-- 
Mike Berry
mikeb@nmol.com
http://www.nmol.com/users/mikeb