Hello Terry.
Thanks for the info on your use of the DEQX. I thought this may be going to far on the thread so I've sent this 'visitor's message' (which I hope is similar to a private message. I can't find any rules about it). Let's see what happens!
From what you say, you find the main benefits are the ability to correct phase, and electronic crossovers. The Room Correction aspect is a bonus. Is that a fair summary? I should add I'm not that knowledgeable on the ins and outs of making speakers, so I probably didn't fully comprehend what you were manfully trying to explain.
I know VMPS pay a lot of attention to their passive crossovers but the fact that he has now decided to offer electronic ones, and also from what I've read, it seems active crossovers are the way forward. I'm not sure I'm ready for that!
In my, so far theoretical, considerations for an upgrade to the Behringer DEQ I was looking at simply replacing it, rather then adding extra possibilities like active crossovers. Hence I'd dismissed the DEQX because, whilst there's a digital in, there's no digital out, only six anologue outs. I have a very good DAC and don't really want to not use it. The Tact XP2.2 has a digital out so that's a better, if not even more expensive, possibility, at least from that point of view.
The irony is that there is a company in Potters Bar where I live (twenty minutes walk from me) that sells DEQX:
http://www.tekcare.co.uk/Scripts/prodList.asp?idCategory=1235
They can hire the machine out for a week to get to know it, although from the experience of others, they aren't too keen to spend time explaining it - perhaps understandable really. Maybe I should try it and not be too attached to my DAC!
Other possible upgrades in the (distant) future might be bi-amping (vertically, passively perhaps) and adding subwoofers.
Anyway, thanks again, Michael. (Hipper)
P.S. My dealer does sell stereo gear but I didn't know about the other stuff. I must ask him!