New speakers for 15*12 room powered by Lamm 1.2s?

Probably used - up to 25K - really depends on how much improvement in sound I get going up in price. I had originally bought the Lamms with the intention of pairing them with Wilson Audio speakers. I never got around to that.  When I upgraded the tubes in the amps to the Amperex pinched waist the improvement in sound was material. It got rid of quite a bit of the brightness in the Thiels.  Rooms treatments improved that even more. Now that I am revisiting I am realizing there are a lot of good options to consider.  

I would not put 25K speakers in a 15x12 room (but that wasn't the question :) )

ATC, Dyna, Wlson or Sonus perhaps? Speakers from a company that's been around....

Judging by the music that you like and your preference for a warm presentation I would take a hard look at the new Sonus Faber Serafino.  Just to be fair this is not what's in my listening room but I think they would be a very good fit for you.  If you're interested in more low end, I'll bet that you can find a used pair of the larger SF Amati second hand in your price range. 

Given you’re coming from Thiels I’d search out Joseph Audio, ProAc, Sonus Faber, Usher, Vandersteen, Wilson, Rockport, and Acora while you’re at the show. Enjoy!

kef ref 3 or blade 2s will work well in that sized room with the lamms 

Dave and Troy

audio intellect NJ

Kef dealers