I've thought for a long time now that it's not frequency response but the ability to hoof a serious quantity of air about without any effort that matters. A kick drum, bass guitar, piano or whatever shifts a sizeable amount of air, to reproduce it you clearly need to do the same, even if you are not aiming for the same volume level. These things can do it without even breaking a sweat, no matter how closely I look at the drivers I can't see them move!
Ahhhh....welcome to Club 15!!! Although mine are 604s and not Golds - but hey, I am a West Coast Yank - so that is appropriate I guess. I don't see the cones move very much on them either. A neat trick is to use some point source lighting - like a low voltage halogen - and angle it at the cones from about 120 degrees to the baffle so that there is a shadow cast in the cone. Then you can see them dance with the other lights dimmed. It is really deceptive how much they
actually move.
I know real Tannoyistas don't like Lancaster cabs, they seem to be considered worst of breed, but these certainly sound really nice. I have no plans to change them anytime soon
The best speakers I have ever heard was a pair of 15" Reds in a GRF Professional (I think) enclosure. I heard them at this guys house here in NZ a few months ago and was floored by them. He had the cabs built by a local cabinet maker, and showed me the 1/4 size foam-core model he made prior to construction, and they look very much like the ones here:
http://www.hilberink.nl/codehans/tannoy18.htm
They truly were impressive, effortless, smooth, blah, blah, blah, euphemisms, etc, ad nauseum - and that just does not do it justice. I almost gave up going home and listening to my OB system. What was the point? The only thing that saved me was that my cabs aren't done yet. Oh yeah, I forgot, I need to listen to music or I die...
Sell the SME and the Hersey's and have the GRF Pros built. Just do it. Beg, Borrow, Build. You won't regret it. Don't think about it. I am channelling you...now...in your sleep...from NZ. Say it with me...GRF Pro...GRF Pro...GRF Pro...
Man, you are one lucky SOB. Years of fun ahead.
David
PS - GRF Pro...GRF Pro...GRF Pro...