Hello folks: I am presently running a 4B-ST for my mains and a 9B-ST for my center and four surrounds. All speakers are MartinLogan (Ascents, Theater center, Aerius i's and Scripts). I am considering upgrading to either a 14B-ST or 7B-ST's for my mains and moving my 4B-ST to center channel duty (and bi-amping). Does anyone have any experience having compared both? The specs are virtually identical, so one would think the "pair" of 7B's would be more expensive -- not so. So, for the extra $500.00 bucks, what will the 14B do that the 7B's won't....? Any feedback would be greatly appreciated. Regards, Herb.