There is anti-social noise and nuisance noise. As others have said already, anti-social noise is between 11:00pm and 7:00am, nuisance noise is between those hours and is also punishable.
Nuisance noise (like anti-social) is not just limited to music, it could be slamming cupboards or doors, dogs barking, etc. Nuisance noise is defined (I believe) by anything which prevents a person from relaxing/enjoying their own home.
You and your friends may enjoy your music, but from experiance, when trying to watch the T.V while having droning music from next door or doors intermittently being slammed at all hours, it is far from enjoyable. Frustrating and stressful, yes.
When you signed you tenancy agreement it should have had contents regarding acceptable noise. It is also worth mentioning that the landlord is every bit as responsable as the tenant for the noise, I believe he can also be prosecuted for it.
Like others have said, maybe you should talk to the neighbours to find some middleground but make no mistake how badly noise can impact on peoples lives, things can go from being civil to ugly in a very short space of time.