Rob, I'm glad you were able to settle things amicably. A personal visit is best. If they're into heavy metal, they really think it has to be played at that volume to be enjoyed, and there might be some resistance. I hope not, Maleke. You need your sleep.
I'm glad I'm in a separate home, because I like to blast classical music when I'm alone!
My son used to blast AC/DC so loudly when he was lifting that I couldn't hear the tv right in front of me. A practical joke on my part helped ease the tension. I put a radio in front of every register (until I ran out) as loud as each one could play--tuned to the classical music station, and yelled down the steps that I was going out.
When I got home, he laughed and said, "Good one! I went upstairs and turned off the stereo. And that didn't work, so I had to go through the whole house, hunting radios. I thought I'd never find the last one!
I'd like to say that helped, but I had to keep pounding the floor with my foot. Ah, the joys of motherhood!