Recommendations for speakers that sound great at lower volume levels.

C’mon, nothing sounds better than a Martin Logan Summit, Ethos, Spire at low volume levels. Crystal clear mids and highs, respectable bass. What more do you want? 26 tube watts will drive all of these speakers to satisfactory levels, especially at low listening levels. There is no better buy, especially on the used market.  $3k for used Ethos? You can’t top that musical excellence in a box speaker. Fogetaboutit!

Props to OP for a great topic that matters a lot in some systems but isn’t often talked about.

1st off, I have to agree with @yogiboy -- I get the best sound IMS with true acoustic suspension speakers in my nearfield/desktop system which crosses over to a good sub @70 Hz. Of the 2 sets that rock my world & sound very good at low volumes, one is a vintage unicorn while the other is a current model:

-- ATC SCM12 Pro passive monitors: the ATCs sound essentially the same at low volume as a higher volumes. That same very present, dynamic midrange and good bass are distinctly audible even with very low volume classical music

-- KEF 103.2 passive 2-way: these big vintage speakers sound very good (nuanced, detailed but not at all bright, with real punch in the mid-bass) at any volume. They’re not designed for nearfield but excel in that application. They rock like crazy at higher volumes, but even at low volumes, it’s all there.

PS: Both pairs are low efficiency (~84 dB/1 meter) & sound best with lots of power--so there goes the theory about high efficiency speakers sounding good at low volumes.

here is another +1 for ESS rebuilt Quad ESL 57's; at low volume evening listening levels they bathe you in sound...... (and Townshend super tweeters with 57's open up spatial presentation and a little more of everything)  

So many opinions. Little speakers that sound good at low volume are efficient and that like tubes. Humm sounds like ProAc Tablettes too me

I have the Klipsch Cornwall IVs and they have a full body sound at low levels.  I've owned Harbeth SLH5 and currently own the M40.1.  I also have the Sterling LS3/6 that I like better than the SLH5.  For low level sound, it's hard to beat the Cornwalls.