As for tonight, try banging on the wall. I don't think anything less subtle will do, and I doubt he'll remember it.
Next, I would write two notes to him that I would stick in his mailbox. The first I would say, "Hello, I live nearby you. I hate to intrude, but there are many times when the noise level coming from your flat is excessive to the point where it is not only disturbing my privacy, but also costing me sleep. I hate to cause a fuss, but would you please turn the volume down so that only you can hear it? Thanks for your help and cooperation."
If that doesn't work, the second one would go, "I did ask you nicely to turn down the noise level, but I can still hear your radio/TV quite loudly. I do work in the mornings and I need to get my sleep. I hate to mention this, but if it continues, you will force me to go to the city council and lodge a formal complaint, which I really would rather not do.
I hope we can come to an understanding on this."
Always put the ball in his court, so to speak. Never get offensive (but do protect yourself if you should have any confrontations face-to-face). I hope your problem is over soon.
Good luck.