One more question.

I have DSP5200HC (not connected because I have no comms cables any more) and I want to try Trifield and/or DD with central channel.

What are variants of adding central speaker?

Can I connect it in chain with LR to get Trifield (digital from slave DSP7000 and comms the same) or is the only variant to connect 5200HC to 861 with 3/4 output coax?

HD621 , 800v4, 861v4, DSP7000, DSP5200HC