BDR Shelf under speaker

I would rather fit the speakers with the BDR cones, then use the BDR Pucks or the Thick Pucks under the cones. Hugh improvement.

BDR carries stud adaptor of a few popular sizes, so you should have no problem to fit the cones under your speakers.

The cones/pucks combination should be cheaper and more effective than using the DBR shelf alone.

Have fun.