I find the sound to be nice but how many watts does it take to get these honeys up to concert sound. I am currently running 275 watts into 8 ohms into them. My old Boston A-400's kicked out more sound then these do. Let me know your thoughts. Thanks
Welcome to the forum. That is a great deal you got on those Sequels. I have a pair of the original Sequels, and they still are performing wonderfully after all these years...
As far as "concert volumes" I suppose it depends on what you mean by that. If you are talking about a concert with the National Symphony Orchestra, or Diana Krall, any decent amp (and by decent, I mean something that you probably DIDN'T buy at a big chain store) rated for 1-200 WPC into 8ohms should be sufficient.
Remember though, that your Sequels are actually a 4-ohm speaker, and therefore they will present a VERY difficult load to many amps. Pretty much all the "consumer" brands will crap their pants when asked to drive this load to any volume. You need something high-quality and high-current like Sunfire, Plinius, Bryston, Krell, Carver, Monarch, or some such brand to get the best out of your Martin Logans.
If you are talking about getting that sort of ear-ringing slam and punch that you'd experience at a heavy metal rock concert, then maybe you should go back to your Bostons...

Electrostatics aren't generally designed to give you that sort of "impress your buddies" bass slam. You CAN get it, with REALLY big amps and maybe the addition of a Subwoofer, but to be honest, if what you want is 120dB+ rock-concert ear-ringing volumes, then I'd suggest saving your money and getting some Cerwin Vegas and a couple of Crown or QSC Amps. The money you save on gear can be put toward getting some really awesome concert t-shirts and a couple cases of Bud for the groupies...
--Richard