Speakers sound too bright.

To rule out a speaker being wired incorrectly internally and assuming you have your speakers hooked up correctly, just play tracks 22 and 25 from this — no need to mess with resistors and such. Left should be left, center should be center, and right should be right and if all that lines up your phase is fine. I continue to think it’s break in, but you should consult your dealer to get their thoughts as well.

http://www.youtube.com/playlist?list=OLAK5uy_ndrls3SVVIl_vwa6lSQILyH7DnQGCevqg

While checking internal and external wiring for correct phase is always a good check (noting internal wiring checks a difficult task that may void warranty) and out of phase wiring will potentially cancel or reduce bass output, cause potential, perceived brightness due to lack of base, it also produces a characteristic hollow sound and incorrectly wide staging effects.  I recommend you check but do not consider this a probable root cause if you are not hearing the characteristic hollow sound and staging effects.  

If you had speakers in the same room that sounded good to you, return the speakers.  I had the same issue with B&W 702 S2 towers.  The dealer told me to burn them in for 100 hours.  4 days later they sounded the same.  I returned them.  Life is too short.  A lot of good speakers available that will sound good to you in your room.  Suggest buying from a dealer or direct from manufacturers that will let you buy, try and return if necessary.  

Just make sure your positive outputs from the amplifiers is connected to the positive inputs of the speakers and same with the negative side. Also get rid of the jumper straps.