Possible bi-wire mode overlook on receiver?
I would have posted this the day after your initial post but my account hadn't received posting privileges yet... sorry.
Under the speaker 1 setting on your receiver have you selected "normal" or "bi-wire" for your front spkr l/r on the xr55? If you haven’t switched it over to bi-wire on the receiver I would think the symptoms of what you are describing would mimic your physical bi-wire set up but with the receiver still playing it in the "normal" mode.
BTW. I own this receiver after having a Yamaha 1400 for 2 years... the detail/clarity/crispness is hard to match at it's price point and I can notice this with an Athena speaker (AS-F2)x 4 set up! However, (if it's not obvious since I'm posting on this forum in the first place.)... I can't wait for my 340se x3 front/170se x4 setup to arrive that I ordered last week to match to the panny. I hope to be getting the 340's by March. The 170's should get here any day. I’ve already looked over the bi-wire set up that would apply to the 340’s on the panny manual if that gives an idea of how excited or geeky I am considering my current speakers aren’t even capable of biwiring.
-Joe