Hi Bob,
A point that I addressed some time ago that hasn't arisen here is that at low volume levels, our hearing is very insensitive to low frequencies, which is why we tend to find speakers lack oomph at low listening levels. It's not a function of different speakers; it's the nature of human hearing!
These curves (the Fletcher-Munson curves, named after the researchers who first investigated this phenomenon, were updated in later years) actually show how are hearing sensitivity to different frequencies operates at different sound pressure levels.
Older receivers and preamps always had separate "Loudness" controls (not the volume) that compensated for our hearing losses as we turned down the level by gradually boosting bass and a little upper treble. Some of these were crude switches that inserted a 10-dB bass boost, so they fell into disfavor.
Yamaha continues to offer a sophisticated Loudness control on some of its receivers and preamps.
Lots of A/V receivers also offer a "late-night" mode in the setup menu that inserts a digital compressor on the Dolby Digital or dts signal, removing the huge dynamic range swings so you can listen at low levels and still get some subwoofer information without waking your neighbors or family.
Regards,
