Backyard Rez...lol
Do you just glue acoustic foam to a floor tile and glue it to the inside of the speaker? What kind of tile do you use? I have some old speakers I'm refurbished and do not want to use no Rez...but Backyard Rez...yes, that sounds perfect.
That'd be "FauxRez" made by ACE (aww, close enough) Speaker Supply.
Remember that there's two things combined in NoRez. Damping layer and the Stuffing layer. They're connected for convenience, but really don't have to be. Use the densest vinyl or even linoleum floor you can find for cabinet wall damping. Acoustic foam, f-glass, polyfill, etc. for the stuffing.