Dynamics at lower volumes?


Assuming appropriate source material, what technical characteristics of speakers/amps contribute to good dynamics at low to moderate volume levels? Are there are any speaker or amp designs that are thought to generally be inherently better at producing good dynamics at lower volumes?
midranger
Horn speakers have a greater dynamic range than any other type, not only on the loud end, but also the soft end. Elizabeth's suggestion of the electrostats is the next best choice for soft dynamics.
If you are talking dynamic range - it just can't happen at low volumes. In valid question.
6550c - finally - adherence to a definition - correct. My guess is that what the earlier commenters meant was either (1) that the lowest level of the recorded sound (i.e. the first few seconds of Verdi's Requiem for example) was audible - thereby being able to hear all of the music; or (2) it "sounded" loud (rich, lush, exciting, 'dynamic' or some other subjective term) at low volumes. The first is limited by the acuity of one's hearing. The second was once accomplished by a "loudness button" in consumer recievers (never to be even considered by an audiophile lest consignment to the dungeon). The loudness effect is now accomplished by speakers designed with a non-flat frequency response - so you have the dreaded "loudness button" in all of the time.
Horn based systems deliver clarity, and dynamics at low volume. Some single driver systems are also quite good at low volume. The same can also be said of lower powered triode tube gear, when such gear is also running nowhere near full output. Put the two together and you have the best combination for low volume listening.

I also like electrostatic speakers for low volume listening because of their clarity and ability to clearly convey small volume changes, though they cannot fully benefit from low-powered tube gear.
Efficient speakers + high power SS = dynamics at lower volumes.

I recently experienced this listening to a pair of Acoustic Zen Crescendos and an Ayon CD-2 powered by a Wyred 4 Sound STI-500.