@thyname Obvious first step. Just wondering how a sub that goes down to 15Hz at best will interact with the floor stander that goes to 20 Hz. My room acoustics are good with little to no standing wave problems.
As to appropriate crossover frequency found the below:
"For music listening, using full-range Wilson Audio loudspeakers, the best option is to select the lowest possible subwoofer crossover frequency to start with (30Hz-40Hz). Listen to the results and adjust depending on if the LF sounds accentuated/elevated/ pronounced or lean/thin. While room acoustics play a big role in this calibration, the subwoofer crossover point is usually between 32Hz and 45Hz with an 18dB per octave roll-off while leaving the main loudspeakers functioning with no low frequency cutoff." From Wilson site