Around here the police won't do anything about loud music/loud anything inless it's happening between 10PM and 6AM.
So maybe you should check your local laws before you make a big stink about it to the police.
Or,..... ask some of your other neighbors to come with you to speak to his parents about it.
I'm sure if more than one neighbor complains the parents would put a stop to it,....
Good luck.
Loud neighbors suck.