I need speakers for low volume listening -

I have much experience with speakers that sound good at lower volumes.
The Harbeths as mentioned are good.
Also I would add, not knowing budget:

Kudos Cardea C10 or possibly C1
Joseph Auduio RM XL or RM 7
Linn Tukan or Katans
Merlin TSM
Neat Acoustics
Audio Note ANK

Have you considered headphones?

While there are many good suggestions here, for truly good lower level listening, you need either a speaker that will allow you to adjust the tweeter, midrange, and woofer levels, or you need a good quality equalizer.

This is due to Fletcher-Munson which cannot be ignored if you want quality listening at low levels. Highs and Bass will need a slight boost for the frequency response to be "heard" accurately.

Nearfield listening will also help, but not like adjusting the speaker, or quality equalization.

Bose Radio Dude.

Zu Superflys - I had these in my home for several days and was very impressed with how well they were able to reproduce all of the music contained as well as the emotional expressiveness at low volume. (Driven with 6C33C SETs.)