If this person has non-traditional sleeping hours, that may account for why 3 pm was a problem. You really do need to investigate, as described above, to find out how much of a problem your system is really causing.
If the problem apartment is the one below, you might reduce some of the transmitted sound by using an isolation platform under the speaker to absorb vibrations (don't use cones that couple the speaker/stand to the floor.
Dipole speaker so a much better job of focusing the soundfield to a listening area between the speakers. This is because the opposite front and rear polarity causes cancellation at the sides. The large panel types also act like a line source which means that sound levels do not fall off as much for any given distance between the listener and the speaker; that means you can play with lower overall sound energy in the room (again because the sound is concentrated at the listener). I went from dipole speakers to regular dynamic speakers and the difference in sound that leaks thoughout the house was startling. You could look at something like Magnepan 1.7s which are line-type dipoles and don't produce too much bass.
Small stand-mounted speakers will also reduce the amount of bass energy and that might also do the trick. I would look at something like Proac Tablettes.
There is not much one can do in the way of room treatments that would really work. If your place is not carpeted, a thick carpet, particularly with a good pad underneath, will cut down on floor transmission of sound. Make sure all doors are closed and tightly sealed when you play your system to minimize the amount of sound that goes into other rooms of your place.
Good luck.
If the problem apartment is the one below, you might reduce some of the transmitted sound by using an isolation platform under the speaker to absorb vibrations (don't use cones that couple the speaker/stand to the floor.
Dipole speaker so a much better job of focusing the soundfield to a listening area between the speakers. This is because the opposite front and rear polarity causes cancellation at the sides. The large panel types also act like a line source which means that sound levels do not fall off as much for any given distance between the listener and the speaker; that means you can play with lower overall sound energy in the room (again because the sound is concentrated at the listener). I went from dipole speakers to regular dynamic speakers and the difference in sound that leaks thoughout the house was startling. You could look at something like Magnepan 1.7s which are line-type dipoles and don't produce too much bass.
Small stand-mounted speakers will also reduce the amount of bass energy and that might also do the trick. I would look at something like Proac Tablettes.
There is not much one can do in the way of room treatments that would really work. If your place is not carpeted, a thick carpet, particularly with a good pad underneath, will cut down on floor transmission of sound. Make sure all doors are closed and tightly sealed when you play your system to minimize the amount of sound that goes into other rooms of your place.
Good luck.