@ronboco --
Depending on the stability of your hardwood floor I'd nonetheless go with his advice; couple, not decouple your subs to the floor. The REL guy has no interest in promoting or selling an(y) accessory that will likely have the product he actually does sell perform differently/worse than what and how they intended. Nothing conspicuous about that.
With my own subs (+200 lbs. each), also placed on a very solid hardwood floor, I've placed a "wedge" (actually it's a few mm's thick piece of hard plastic used for distancing tiles and such) centered under the front, bottom edge between that and the floor of each sub, that are otherwise placed directly on the floor. This stabilizes them completely so they don't make any rocking motions on their floor position, and also has upper, backside edge of each sub lean directly against the front wall. This fully secures them to "fire" off bass in an unwavering fashion, regardless of SPL.
In your case with REL subs I gather they have some kind of rubber footers, and I wouldn't deviate from that as these will couple the subs quite effectively to the floor. That would be my outset. If on the other hand you feel the REL's (how many?) sound too boomy and undefined, having tried out a range of positions, then, and only then would I consider decoupling them. Just my $0.02..
... I just got off the phone with the REL guy and he said NOT to put footers on the subs as they perform better coupled to the floor.
Depending on the stability of your hardwood floor I'd nonetheless go with his advice; couple, not decouple your subs to the floor. The REL guy has no interest in promoting or selling an(y) accessory that will likely have the product he actually does sell perform differently/worse than what and how they intended. Nothing conspicuous about that.
With my own subs (+200 lbs. each), also placed on a very solid hardwood floor, I've placed a "wedge" (actually it's a few mm's thick piece of hard plastic used for distancing tiles and such) centered under the front, bottom edge between that and the floor of each sub, that are otherwise placed directly on the floor. This stabilizes them completely so they don't make any rocking motions on their floor position, and also has upper, backside edge of each sub lean directly against the front wall. This fully secures them to "fire" off bass in an unwavering fashion, regardless of SPL.
In your case with REL subs I gather they have some kind of rubber footers, and I wouldn't deviate from that as these will couple the subs quite effectively to the floor. That would be my outset. If on the other hand you feel the REL's (how many?) sound too boomy and undefined, having tried out a range of positions, then, and only then would I consider decoupling them. Just my $0.02..