I need speakers for low volume listening -

another vote for harbeth speakers. Very full sounding at lower volumes unlike most speakers their size/efficiency!!

Spica TC50 for sure, beats anything I have tried against them at low volume except maybe Spica Angelus. Have not owned TC60s, but probably good too.

This subject comes up regularly, so you may want to check past discussions. Quad electrostatics usually get the most votes.

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?