Yes, you will hear the club at times. I had an oceanview guarantee cabin on Koningsdam in March, and I was assigned a cabin directly below. The good news is: it is an *extremely* convenient midship location, which I wouldn't hesitate to book again.
I heard music (and muted cheering) on only 3 nights: 2 nights I heard nothing after 10pm; 1 night music was until about 11:30pm. I'm pretty sensitive to noise when sleeping, and the dull thudding of bass was A) not bad enough to keep me awake without earplugs, and B) not audible with earplugs.
I strongly recommend always packing earplugs while traveling, but especially cruising. There are any number of sounds that ships make (rattles, bangs, creaks) aside from the music. For what it's worth, I find the lido chairs scraping above at 5am, is FAR far worse than any club or show music.