There are a couple of different crossover options available Mark. My plan is to finalise the configuration of the speakers and the best crossover parts then do a final point to point hard-wired crossover. It may be 2 way, 2.5 way or I may end up biamping with an isobaric sub. I am in no rush. I’ve drawn up a design for a clamshell isobaric and may likely give it a go but to be honest I’ve got fairly much to bass happiness with it as it is. Certainly only dance and trance is MIA but the Harbeths do that easy. For anything else the Pap horns are doing it completely.