Best speaker 3k to 4k used?

You might cruise over to Greybeard Audio's site:

http://www.gbaudio.com/

Greybeards are superb quality, and will provide very natural, fatigue-free sound. They are having a sale of their inventory because the designer, Tim Wright, has a serious health condition. So you can get a killer deal on the speaker of your choice - they come with free shipping and a 90-day warranty (which would easily cover any manufacturing or driver defects, though I very seriously doubt Greybeards would have either).

The Greybeards are among the most musical speakers I heard at CES 2001 and 2002, and among the most un-boxy sounding (I own and sell full range electrostats, so I'm pretty intolerant of boxiness). Superb midrange, very solid bottom end, and if anything maybe a wee tiny bit laid-back in the very top end. This keeps them from sounding edgy with mediocre recordings.

I have absolutely no financial interest in Greybeard.

Duke

I just bought a pair of how demo Silverline La Folias direct from Silverline at a very substantial discount but there's also a pair listed here for $4000 OBO. I haven't received mine yet but a brief listen at the show in the Spring and the great reviews at www.silverlineaudio.com have me convinced that these are terrific speakers for the money at the $8000 list -- let alone at less than half that amount. They could be a bit too much speaker for your room, though.

Never heard this combination but why not consider Martin Logan? They sound quite good with Krells,may do even better with Gryphons.The choice of dynamic speakers is endless.Just make sure to keep your S100/Tabu combo,no speakers in this price range are worth replacing them.