I'd like to thank everyone for their help to date. Very much . I will need a bit of time to do the SPL meter / test disc sort of thing so I'll let you know how that works.

To finish off the last bit of questions (which I don't expect a reply to!):
-> Alan Lofft and I were going back and forth earlier this year about my other sub (which I have tried in the same position as the EP-500). Reason? There is a minor null spot in my room that effects the EP-500 but not the downward-firing sub. He was curious... regardless I have now placed the EP-500 in a place that avoids the null spot.
-> The room is 12'x22' (x8' high). The null spot strangely enough is between 4' and 6' on either side from the front. I have french doors mid-way on one long side and directly opposite them a smallish fireplace.
-> Yep, I may have the EP-500 way too 'hot'. As Jack said, without the SPL meter its hard to tell. I'm only comparing it to my other sub + the C-5 towers where the (mostly acoustic) bass seems better 'defined' - but that's by ear only.
-> the changes suggested by everyone *have* made a difference to the better. By 'sharp cut-off' what I mean is that there are some notes, mostly noticed in cello, (yep I listen to all kinds of stuff, I also like jazz, Paul Weller, and Peter Green era Fleetwood Mac) that seem to 'roll up' from the EP-500, go sorta 'flat' and then get picked up by the NHTs. Nothing real dramatic at all, just not quite as 'full' as the other system.
-> and yes, on ambient music the system does now sound a lot better. I do think that I had 'duelling crossovers' going for a while there.

Again - thanks a lot guys. No reply expected... I gotta do some SPL work now.


ken