@Andolink , Because of this thread, I have been noticing the 120 Hz hum in several buildings. If and when I have accessibility to the source of the vibration, have found it is the fan motor (60 Hz, USA) for a ventilation system.
Oh, okay, I didn't catch that detail from your first post. I don't have a WXC-50, but I would like to think the AUX IN would provide gain through the volume control and PRE-OUTS. Hopefully, someone with hands on experience can give you a definite answer.
Your condition is very common, just because walls create standing waves. As mentioned above, try to re-position your speakers and/or the listening position, if possible. Next step would be some room acoustic treatment. EQ compensation will cause your system to use more amplifier watts and make...
These were mentioned earlier in this thread, but after watching a B&W factory tour and speaker assembly video, the 801 D4 Signature is more attractive to me than before. Yes it is overpriced, as are many of the interesting speakers in this thread, but still it is one more fascinating example...