I think as a general guideline highly efficient and easy to drive speakers are going to sound less compressed and more dynamic at lower volumes. That means a 4 ohm floorstander is probably not going to fit the bill. Monitor speakers are inherently more efficient than florstanders but you might want to consider some designs that are higher than 4 ohms.
As for a recommendation I'd suggest a monitor speaker from Green Mountain Audio. Not only are they generally efficient and easy to drive but the phase and time coherence will really aid in hearing dynamics and detail at low volume.
As for a recommendation I'd suggest a monitor speaker from Green Mountain Audio. Not only are they generally efficient and easy to drive but the phase and time coherence will really aid in hearing dynamics and detail at low volume.