Noisy Nigger Neighbors
You've lived in an OK apartment for years, and then THEY move in. You've now got "Night of the Thumpasorus Peoples" over and over and over (or it could be daytime). If you ask them to turn down the bass, they'll say "hey, we're cool!" yet keep on doing it as if the conversation never occurred. You will always be the "complainer" and they will always be innocent victims of your "unreasonable" expectation that noise rules be obeyed. NNN is how ghettos begin.