Some other factors:
1. kps. I have Room Noises at 320 kps, which is great. Really brings out a lot of the crisp and clean sound quality. You may have a lower kps, I don't know.
2. Speakers: If you have crappy speakers, it may be harder to notice it. (although my speakers are run of the mill).
3. Like I said, if the other instruments go from soft to loud (like in Marvelous Things, you may lose where the bass "was going", but it is still there, which leads me to point number 4
4. Sometimes the bass is more felt than heard. I find that I can sometimes feel where it is without actually knowing what's the general bassline being played.