Hello, I have a Herman Kardon AVR520 hooked up to polk RM6000 speakers. The problem i face is that the output of my center channel is very poor. I really have to bump up the volume sometimes to make sense.In fact while playing DVDs the dialogue part seems to be delivered only to the center channel and makes it worse.If i bump up the volume, any sorround effects hit a high decibel level.So, it becomes a cat22 situation for me. For better dialogue i need to bump up the volume but that is too much when there is good music or sound effects. Any suggestions/help here would be very useful.