Tenant Playing loud music in backyard

[Sami Gren]

please let me know your thoughts on this situation (not on myself, lol)

I have a new 7 unit multi family,  and one family has been sitting out in backyard with blasting music from their car, 

I know I can explain this in big paragraphs,  but as experienced landlords/managers I know you understand exactly what I wanna know....

I must point out.. it is an area that you can hear loud music, but it doesn't need to be my included..... (?)

(Nobody has complained yet to me)

Thank you