Thank you all so much for the helpful replies.
I have tried to set the phase to 180 according to willands suggestion, it seems to help a bit, but it's hard to tell, I will try to have it at 180 for a while.
I have set the crossover to 90hz on the subwoofer itself, because setting it on the receiver didnt work. I will try other locations.
Should I think about upgrading the old Yamaha RX-V595 receiver? And what price range should the new receiver be at? Im hoping around $800
@pbphoto: Thanks for the help. I will try your suggestions and report back on the result.
Btw, the speakers and woofer are fantastic, well done Klipsch!