yeah I have been having some issues, while I don't have issues on 3, 4 it almost feels like the calibration for mic and drums are different. though I think that was actually an issue with the mic that was patched a patch or two ago. I am still waiting for my coldplay tracks before I play again :/Personally autocalibration isn't working very well for me. I have a 55'' HD TV connected to a receiver through HDMI, and they give me completely wrong numbers especially with video. Audio is more on point, but it's still incredible difficulty for me to calibrate Rock Band 4 properly. It also doesn't help that it feels like the game goes further out of synch the longer you play. It's just extremely frustrating to constantly have to exit the game to fiddle with the calibration settings when nothing you do seem to improve it. .
Hopefully Harmonix will improve calibration it in the future, at least they have been asking people about their TV's and calibration settings, so maybe they are onto something.
Then again for others, it was just a matter of autocalibrating once and the thing worked flawlessly. So it's really hard to say.
though since I have lego rock band tracks that will help a bit.
but damn it the scientist is such a good vocal warm up song :/