I listened to the Amazon samples. It may be the low quality samples, but there is a rhythmic snapping sound which would be consistent with a really deep sub bass that is clipping.

To me that sort of thing is ok sometimes. like if your bass distorts in the climax of a song it might give the sense that the music is so powerful there is no containing it. But, this seems like it's throughout the whole cd and was just an oversight.

It's actually a common compression artifact that occurs when the release time isn't set long enough, so the bass distorts.

My guess is it's a mastering oversight.

Tisk, tisk.