I know the Linn Index, it can have very good bass when next to the wall. It can be up to 8 inches from the wall to have the bass reinforcement effect. Away from the wall it still has a rich sound, it just doesn't have the lower 'thump'. So I doubt his system is light sounding.

My boombox actually sounds pretty lean -- a bit bass shy. So I have the bass controls cranked up. I would suspect that yours is placed in a place that is not friendly to its speakers, or there is a problem. Try moving it to some other locations so you know what the problem is.

If it's not defective, you can reduce the bass by raising the unit from the table top an inch or more. Try putting some kinds of feet under it or something. The higher it is off the table, the less the bass reinforcement from the surface will be. You can get some rubber feet and stack a few of them for a permanent solution.