Dont elevate the sub, or De couple it from the floor as this will tend to make things sound dead, you will kill and rob the life out of the sub, this is a key quality that REL subs have. REL's not only produce bass they have a musical sound that works and enhances the main speakers, this will be lost if you isolate the sub from the floor, use bass traps or other resonance absorbing material in SPECIFIC areas to combat this.
Matt M
Matt M