Here is an interesting experiment you may want to try if you have the tools to do it...
In professional PA, many devices are used to shape sound. Get an Equalizer (Almost any will do, 10 band is fine), and stick it in your audiophile system. Boost the midd-bas and mids, cut some of the low bass and the highs. Now play your system at low volume... Sounds a lot more like background music.
If you want to really get the full effect, get a sonic maximizer and a compressor. Stick the sonic maximizer behind the EQ and turn it to the max setting, then set the compressor so it is always compressing except on the lowest music levels; if you have a song with a fade at the end, set the combination so you only hear about 3-4 seconds of a 15 second fade.
Turn the system way down and use as background music... You too shall be amazed at how 'pleaseant and backgroundy' the music sounds... I use two cheap Sony 300-disc players in combo with this to do non-stop background music for parties; according to guests it sounds 'great' on everything from cheap outside Inifity, to B&W to Vienna Acoustics.
If you ask me... It sounds 'sweet' but is unusable for criticl listening. As background music, it is great.
(PS: I have a small FM transmitter hooked up to this setup as well, and just tune radios throughout the house and yeard to the same signal... Even coming out of a $9 clock radio it sounds decent... :)
Niels.
