Yes, speaker placement is the most important aspect in getting the optimal sound in a room. Be patient and you'll be rewarded.
In addition to all the excellent advices posted above : do check the wires are correctly phased(+/-), speakers: L & R tweeter-woofer outputs are ok and the port holes are not plugged if there is any. Also, I'll 2nd Xti16's recommendation, fill up the metal stands if you're using one which will help tame the ringing (however small) in some instances affect the image and focus.
Further improvements can be done easily by using acoustic panels right on the 1st reflection points.
You got a great set of speakers, enjoy.