With your subs it probably doesn't make sense. With a typical mass market sub and a suspended floor, it does make sense. A typical sub transmits vibration directly to the floor, even with feet. The floor is then vibrating and "adding" to the sound. Removing that means you hear the sub only not the sub and the floor. I've done it with multiple subs, both on suspended and concrete slab floors and it helped in both rooms. With my Empire however, it didn't make any difference. On my old sub, objects would vibrate off of it. On the Empire, there's almost no vibration transmitted to objects in contact with it. In most cases, it will be audible in certain bands, and with my previous sub (15" in a sonotube, Adire Tempest tuned to 17.5Hz on concrete slab) it made a very noticeable improvement in the upper range. In the same room, same location, the Gramma made no difference with the Empire so I removed it. Never took measurements, but the difference was audible with the Tempest. I was not EQ'ing that sub. It is a small thing that may not matter to some, but small things add up. Speaking from experience not theory.