Acoustic Resonance on a321's ?
Only ever noticed this on the 321's as pax, never heard it on the 74,77, or 73, however the last two/three flights as a pax on the 321's out of Eire I have definitely experienced resonance at low/sub/taxi power, infact it became uncomfortable after a minute or so, so much infact I was glad of the spool up to the TO run.
Is there a known rpm range to avoid for the powerplants on a321's ?