Low volume listening dynamics

All the answers are here...low ambient noise, good 1st Watt, effective tone controls for shaping the source to sound balanced at your listening level, and controlling the room's reflectivity around the speakers.  I disagree about needing high sensitivity speakers entirely.  I would say a bigger factor is to have speakers that are not lacking in bass extension, b/c at low volumes, that exacerbates the lack.  I agree with Erik in recommending looking at Yamaha...if the model has their variable loudness, like the AS701 or AS801.  Interestingly, their new higher end models drop that feature...although they do have bass and treble controls (with unspecified characteristics).  I have a vintage McIntosh C20 that has a fantastic variable loudness control that really works well.

Mike, sitting closer is just turning up the volume. It certainly helps negating any room problems.
The beauty of having 8 foot line source dipole speakers is that you are always near field even 12 feet away. 
Irregardless of the equipment being used and the room are in you can not magically overcome the Fletcher-Munson effect. Bass and treble have to be boosted to match the volume level or you will be missing low bass and detail. 
The only way to overcome this without an advanced digital system is to adjust the volume until things sound right and there is not a single level. It depends on the way the recording was mastered. Some records don't sound right at lower levels others hurt if you play them too loud. 
This is for serious listening. For background music it really does not matter. 

Not trying to open up a can of worms but I did get some low level punch when I got a dedicated circuit with only the amp on the line. I also listen mostly at low volumes. Speaker placement/room characteristics I'm sure help...but probably the thing I've noticed the most is that component matching really helps.

That said, my Primaluna Evo 400 power amp does a wonderful job with low volume bass.  
 

Thanks to everyone for sharing your expertise and experiences. Gives me a ton to think about.

Your ears are NOT old enough to remember loudness.
Buchardt seems like they have figured it out.
The future.