If you were playing trash I'd whine about it too, but knowing you it's fire so they need to calm down.

Here's how you tackle this, agree to turn it down for now. But you're on reserve now. You're waiting for your opportunity to strike back. The second, I mean THE SECOND, you hear any music that bass nob goes on max along with the volume slider and Love Sosa (preferably with the intro) blares. Once the song ends you pause it and make sure they stop. Rinse and repeat until they understand they can't play garbage unless they want to hear and feel Almighty Sosa Otto. Next hurdle is the screaming children. Now this one is a little tricky. Since I know (hopefully) that you don't have any young children nearby you're gonna have to improvise. Now what's as annoying as someone's screaming child? You're god damn right, that annoying buzzing noise that shitty fluorescent lights sometimes make. Step one is the same, bass and volume on max again, now you need to find a youtube video of this noise. And for christ's sake make sure you run ad block on youtube, the only thing more embarrassing than an ad would be the sub blowing out. It'll drive them crazy, do it until the kiddo chills, maybe even a little longer just for good measure.

This has been how to deal with neighbors, by imgur.