Low volume music

Tubes compress dynamics which clearly helps at low/med volume. I also enjoy my Quad subwoofer, which has a remote and four volume/crossover memories. At few DB boost at low volume can help a lot on some recordings.
I second the general notion that English loudspeakers are more likely to be low volume friendly by design than domestic production.

HP once noted that speakers also have signal to noise ratios, but one rarely sees any specs on the subject. This remark was made during a review of the Pristine ESL (Soundlab). The ESL's which I have had always struck me as very quiet - perfect for late night listening. Tube amps also helped, but only if the transformers did not buzz (a very common problem).