In my recent review of the iCAN amp I included the following observation in my discussion of the xBass boost that is a feature of that amp:
However, it is not just on bass heavy music that this X-Bass feature comes into play, even though the bass boost effect is clearly in the lowest frequencies and does not mess up the mids. I will quote Srajan from a recent review of the Zu Audio Submission sub-woofer on his 6moons.com website as he describes very clearly why low bass matters even with music that has little or no bass frequencies:
If you're still out in the cold wondering why one would even want 20Hz bass—surely that's fit only for the boom-truck brigade—the answer is simple. It's not about any rave, disco or reggae excess. It's about scale, soundstaging, ease, color saturation and rhythmic grip when kick/bass drums and related beat makers add weight, kick and pitch intelligibility. It might have been British REL subwoofer firm who first did girl+guitar type dealer demos with and without subwoofer. This demonstrated how recording-venue cues are seemingly associated with very long wavelengths at very low amplitude even on material that's apparently devoid of any real bass. That effect is very real. It's the first thing Martin Gateley, designer of the Wave 40, said when we added the Submission. More scale. Aside from the primitive obvious of more extended bass, the far more impressive transformation related to space and size. Everything instantly grew bigger and deeper. Save for hearing synthesized infrasonic chicanery on ambient and electronic albums which regular speakers can't reproduce fully, the primary benefit of building out the lowest octave thus isn't about more bass per se. It's what mostly instinctual (rather than directly audible) bass adds to dimensionality and participatory involvement.
I think the above explains part of what I am hearing with the X-Bass engaged. On some music with a strong low bass component, the effect is obvious and quite enjoyable. But on less bass heavy music, I still hear a fullness and completeness to the sound that perfectly complements the added air and space of the 3D effect (see the review efor more about the 3D efect : http://www.head-fi.org/t/654405/ican-amp-review-a-new-amp-that-gives-you-more-more-bass-more-soundstage-and-more-detail). The two together create a more realistic sense of music being played in a venue instead of inside my head. The added presence in the low frequencies gives the sense of how music pressurizes the air inside the room when using speakers, and without it the music seems thin and lifeless in comparison.
I wonder if anyone else experiences the same benefit of a boost in the bass on music that does not have a lot of bass. I do not listen to a lot of bass heavy music, but I still find I prefer having the bass boost turned on when I listen.