

A friend of mine had a similar issue. Also UK, West London a guy was blasting his car stereo every night in front of his garage, often till 8-9 pm, in some cases during the night while having some weird people over. It was very loud, walls vibrating, etc
Various neighbours called the police on him at least 5 times but nothing happened, he turned off the music for a while, ignored the cops and turned it back on after they left.
They told them they need hard proof to do anything, this would involve getting a regular recording of the music and they should measure the decibels and vibrations to prove how disturbing it is to start anything. It was just the most bizarre way of telling people the local council and police will do nothing. Who the fuck has this kind of equipment and knowledge to do this?
Needless to say nothing happened. My friend moved to another place because of work within 6 months.
I do hope in your case the local law enforcement will be more competent, I wish I could give you an actual advice instead of a story :(
Oh look, its Serj Trunkien!