I highly doubt the 602s are even able to produce enough bass for most people in these days of over blown bass. A small bookshelf is just not capable of reproducing good low bass compared to a floorstander or subwoofer.
I can get adequate bass out of my M22s but if the music is not very bass heavy the M22s will sound to be lacking bass to some people, when it is just the way the music is recorded.
You can always bump up the bass level on the receiver a few db to enhance the bass, no harm in doing this.