whats seems to be the problem? Have you tried them without the sub? How far away are they from the the wall /corner?
If they are for 2 channel only , I would get a 2 channel receiver . My chorus lls sound better with a 2 channel receiver than with a home theater receiver. Ive tried an onkyo 717 , an itegra home theater receiver , an sx780 pioneer 2 channel ,a parasound receiver .
The 2 channel always sounds better to me and its not just a slight difference. the chorus always sound tinny , no bass on a home theater receiver, put it on a 2 channel receiver and they wake up .