klipsch kg4's have no kick in the mid, need mods

I have a klipsch surround system including the kg's, and a velodyne cht15 sub. I know this is not state of the art, but I just need to work with what I have for now uless their is a cost effective alt. I have stongly considered selling the sub for a sunfire or m&k because I listen to 70% music. I am trying to a find a clean sounding 6.1 receiver right now also. I am looking for mods for the kg's or perhaps a recommendation on a different setup. I have no mid range punch around 150hz. Is this a sub problem or an amp problem or what. I have played guitar for many years so my ears are sensitive to good sound but my pocket book has other obligations right now. Any help will be appreciated