We just got back last week. Had a Red Room on the 30th floor (3011) to be exact with an AMAZING full on view of the Eiffel Tower and the Bellagio fountains. And yes, we could hear the base. I actually didn't hear it the first night (so tired slept like a baby), but my husband mentioned it to me in the morning, that he could hear this "booming" sound until about 3:30. At first I thought he meant the fountains, but then I realized that those end before midnight so that couldn't be what this was. The second night I heard it too, and realized it was the base from the nightclub!! Didn't think it would be possible to hear 30 floors up, but, guess so!!
Anyway the rest of our trip was days the nightclub was closed so we didn't ask to change rooms. It was nice and quiet then.