Much will depend on the construction of the building. We live in a modern house with brick walls and concrete floors, so I decided to do an experiment. I am now playing the main systrem in the living room, while I am sitting in my home office a floor above. I have been playing a Brahms violin concert and Bruce Springsteen Born in the USA at a pretty loud level and all I hear are very faint noises coming through the doors, and no booming bass. The main audio system has three subwoofers with a total power of 1200 watts (an SVS SB2000, a Kef Kube8 and a B&W PV1d), equalized by MSO).
This underscores that there are three ways in which sound can propagate. First, through openings like, in my case, doors, but also along piping and various ducts. Second contact noise. This is probably a big issue in timber framed houses. Dual opposed drivers may help a bit. Third, propagation through the air. Here my thick brick and concrete walls with their high mass probably block all sound.
Finally, for the subjective experience of noise it helps if there are no bass peaks - dsp room eq is not only key to good low frequency sound quality, but also to keeping your neighbours happy.