Best Late Night Low Volume Speaker

I use my Merrill single drivers all day long as computer speakers. Great with low level listening. The other advantage of small single driver speakers is there really is a lack of bass to disturb others at night.

There is no such thing as magical late night, low level listening with speakers. All systems have a volume where they really start to shine and it is not at a low volume. Headphones may be what you need or for whoever you are inquiring for.

I see what you mean, Rrog, but you know, if the room is DEAD silent, the level needed for good sound decreases dramatically.
Late at night, when I can hear a single car pass on the main street 3 blocks away, that is when you can hear far into the music. And do so at a level that won't disturb a sleeping person in the next room.......

I think that in generally a speaker that is not laid back and perhaps even forward sound better at low volume. Not to much bass either. If the bass is tipped up or heavy then the highs can sound tipped down and lost at low volume. Also heavy bass tends to wake up neighbors. Mine tend to get angry and have NRA stickers on their car. That combo can ruin a good listening session.

Dealer disclaimer: I am a dealer for Sonist, deHavilland, Esoteric and Kubala-Sosna

I like certain higher efficiency horn systems for very good low level clarity and "jump" (dynamics). But, one has to like horn sound to begin with or find the relatively few such systems that don't have as much of horn coloration or assemble a system from parts.

For more conventional systems I think you should look at something like the Reference 3A (someone mentioned it above), perhaps a classic box-type Spendor (not their floorstanding speakers) or Audionote speakers.

Electrostatic speakers, such as Quads, sound really good at low volume because of their clarity and their speed (good at small dynamic changes). They also have the advantage of being dipole speakers. With dipoles, there is a back wave that is in opposite phase to the front wave. The two waves tend to cancel out at the sides and significantly less energy is put out into the room outside of where the speakers are aimed. When I changed from electrostatic speakers to my current dynamic system (horn midrange, cone woofer, bullet-type tweeter) I was surprised at how much louder was the leakage into other rooms. Magnepans (planar magnetic) are also dipoles, but, they tend to need to be played a little bit louder before the music starts to "jump" so I don't know if they would work for you (but otherwise, they are terrific sounding and not too expensive).