What makes a speaker sound great at low volume?

The Fletcher Munson curve is a reality that cannot be avoided, and although efficient speakers (especially horns) do "seem" to sound better at low volume (I use Klipsch Heresy IIIs at 99db efficiency with a 12 watt per side tube amp) they can’t run from old Fletchmun...if you can live with single ended ins and outs from your preamp to amp, get a Schiit Loki...an exceptionally low noise inexpensive 4 band EQ that seems made for this sort of thing...I don’t use mine that often, but since it doesn’t drag on the signal (utterly transparent when "out of the loop") it’s always there when needed, generally to add sparkle to dull sounding recordings or kick Fletcher Munson in the gonzagas.

Please..it's BASS, not base...unless we're talking about footers or stands or fans...BASS. Thank you. Also, looking for low tones in audio is called Bass Fishing...they have tournaments...here's a thing, my Schiit Freya has a clicking yet interesting "128-step relay attenuater" that purports to keep levels equal in each channel at any volume and it seems to work. And that Loki...can't say enough about how well it works, although maybe I just did.