preacher is nice...

I think the best way to settle this would be to talk to them... See what they do... The talk to their neighbors tell them you a nice way to help with the problem. One morning at a scheduled time you go in the hall way take you amp and as much equipment as you can and play the 18/12 overture. Or any other long piece you can think of that is really annoying. I suggest on a sunday morning. IF they don't have jobs. Then they will be drunk and probably hungover.

If possible talk to the Landlord. But, usually they don't do much.

The other more effective way would be to knock on their door talk to them. Take your quitar and rock out. Tell them if they chill it some you will teach them. And definiately play with them sometime.