I must agree with the comments about Harbeth speakers - which have great rich midrange, well controlled bass and superbly clear, smooth highs. I have both the 30.1's and the 40.2's - which sound very much alike, as do the 3PSR's. When driven properly, they sound a lot like the Quad ESL-57's - which are the best.
While I prefer them driven by the SS Hegel amps (H590 in my case) as demoed by Harbeth at most shows, they can also sound superb with selected great tube amps - which may even give them an even more real, live sound - just depends on the specific set up.