Aren’t 4XO’s larger than 2.2000 as well? That + higher efficiency would definitely make them different and probably more adept at bass in a larger room with more amps.The Walsh 2.2000 just never sounded that good; slightly muddy and lacking in detail. On Peter's rig, they sounded like different speakers - terrific.
My 4XOs are a good match for my current low-budget system (B&K Reference 5 S2 preamp and Parasound 1500 amp). Plenty of clear bass, decent mid range and good high end for me, but I'm old and probably can't hear much above 12KHz or so.
Rather than spend more money upgrading the electronics, I plan to just sell off the Walsh 2.2000 speakers to someone who has a better system than mine.