I've just converted to a low powered setup in a small room. I'm using Omega Super 3XRS speakers (94db)which replaced a setup alternating between Kef LS50's, Harbeth P3's and Silverline Minuets. I couldn't be happier with the sound. Super coherent, very fast with great imaging/soundstage capabilities.
The Omegas have plenty of power and then some for my 4 watt amp and they meet your budget requirements.
Based upon your preferred listening levels, fairly low, you really do not need a super-efficient speaker. Anything with 88+ db sensitivity should work quite well. You might want to consider the Gallo Stradas being sold here on Agon, $499 each brand new. These are very good sounding speakers, Google for reviews...
My first thought was Omegas as Seikosha mentions, Audio Note, Fritz.
I also agree with RW's point about not needing super efficient speakers. I would focus on the tube friendly aspects of the speaker (Impedance vs. phase) more than the sensitivity. I'm thinking harbeths (which I have never heard) or Spendors which I have heard with a 15 watt amp and thought they sounded pretty good.
There is a pair of Zu Soul Superfly speakers here for sale for under 1,500.00
I'm loving my Zu Essence with my 2a3. Very nice at low volumes...
run some Ref 3A de capos (92db) with a 4 watt decware. plenty loud
Zu is nice also look at Tekton
Good single-driver efficient speakers include Zu, Tekton, Hornshoppe, Brines, Goodwin, Hoyt Bedford, Omega, Lovecraft, Blumenstein, Parker, Pi, and Decware.
Consider 45 amplifiers also as they will work just as well for you. Full range single driver speakers (without any crossover) IMO deliver more truism at lowest volumes. I very much like the beauty of simplification, of course there are always tradeoffs. Visit the AA forums of SET and Hi Eff. I fully agree with the direction you are headed in!!!
I second decware, and my 2w superzen sounds great with the tekton lore and Zu omen.
Perhaps Blumenstein Orca.
Have Fritz make you a pair of single-driver standmounts. I have a pair with the 4" Fostex drivers and they really sound good at low volumes. I think they only cost about $400 and they're very well built, IMO.
How do the omega 3xrs compare to the Ls50s and Silverline minuet supreme ?plus
I would check out the Tekton Designs M Lore tower. I know you said no towers but this speaker has a small footprint and has the port in the front of the speaker. There are some awfully good reviews of this speaker out there. It is 95db efficient and a benign 8ohm load. They are $650.00 new direct from the factory. I will find out if this is true next week when I receive mine.....
@Brianportugal...I greatly prefer the Omegas to the Kef's and Silverlines. They image better, are much more dynamic at the listening levels I experience and once you hear the coherence of a single driver, you really do start noticing everything that goes on when you have a speaker trying to make two completely different drivers trying to sound the same when playing music. It's odd, until I had the Omegas, I really liked both the Kef's and Minuets and would have been skeptical that a single driver would have outperformed them for me in the way that the Omegas have.
In the rooms I played the Kef's in, I always had that typical upper bass hump going on that is common with two ways. The Silverlines were better in this regard. Surprisingly, going down to just below 60hz, the Omegas measure the flattest in my room at my listening chair using a simple SPL meter and test CD.
Obviously being high efficiency lets you play them with low powered tube amps too which is a huge plus. If your room isn't too large and you don't blast your music and you prefer tubes, they are worth a serious listen.
My Omega XR3 got tone of acoustic instruments wrong.
Schubert, it's a totally different speaker now. Completely different drivers.
Thank you Seikosha . I can't weight to hear them. Should be here next week