How do your 7B's sound now that you have had them for a while ??
I'm really impressed actually, though they are *really* revealing of the rest of your components, so I guess any Purchaser needs to be prepared to have things laid out in quite a stark way, "warts and all" as it were.
This also means that the Engineering of the Source material can make or break the sound... for example Gary Moore playing Parisienne Walkways "live" is good, but not great, whereas a recording of Alex Cornish playing "Brothers in Arms" live is stunning and resulted in grown men being reduced to tears at the weekend !
I would also add, though you may know all this of course, that room acoustics are *absolutely* critical... some even going so far as suggesting "50%" of the sound you hear is down to the quality of the room; have you got bass traps in all corners, tackling the trihedrals followed by the dihedrals ?
Going back a few years, my bass wasn't great, but once I'd tackled the room, losing all of that horrible "resonance/boom", I was able to crank the volume up by another 30% which makes a massive difference - the bass on Chemical Brothers' "Dig Your Own Hole" now wakes the dead !

(I also think tackling first reflections are critical for widening the sound stage, but that's another discussion entirely ...)
Anyway, I guess my question would therefore be, what components do you have up/down stream and what material have you been playing on the system ? Both might provide some insight into where to make some changes because, from my experience, the "problem" may not be the amplifiers...
Hope that helps !
Ian