Subwoofers "voiced"? There is no voicing possible at subwoofer frequencies. Danny Richie of GR Research addressed this issue recently on his website, in regards to the x/o mod he designed for the new Elac speakers. Voicing involves frequency ranges of larger swathes than a mere 90Hz (10-100Hz). Not even any tailoring, really, as woofers are crossed-over from at too low a frequency to allow or require that. The floor and wall reinforcement you mention effects all subwoofer frequencies relatively equally (in comparison with midrange and tweeter drivers) as far as the subs themselves go, though the dimensions of any given space have an enormous effect on the sound of all subs in that space. With subs it is pure output and room dimensions that are involved, plus non-voicing issues such as distortion at Hz at SPL, time domain behavior (as revealed in waterfall plots), mechanical issues such as motor power versus driver mass, enclosure resonances, etc.
If you remember the work Roy Allison did after he left Acoustic Research, he addressed the issue of floor reinforcement or cancellation from woofers located at certain distances from the floor in his Allison Acoustic speakers by putting the woofer at the bottom of the cabinet, and crossing over to them at a lower than common frequency, with the midrange and tweeter drivers put at ear level. He didn’t voice the woofer, unless you consider floor-loading voicing!