If it's not loud, I don't think there's anything you can do. As annoying as it may be. Can you not use headphones while you're working?
If you can hear your neighbours music and it's persistent, then it's too loud. Everybody makes noise, and we gave to accept most of it - DIY, lawn mowers, kids playing, cars, etc. But persistent music and/or dog barking is not acceptable. Most of us are happy to turn a deaf ear to noise from occasional parties and suchlike, but all day, every day is just not on. It's the neighbours who should be wearing the headphones.
If you can hear it through headphones then I would say that’s loud! When you said it wasn’t loud, I was thinking you meant you could hear it a little bit when it was quiet. I agree with Old Goat that the neighbour should be the one wearing headphones, I was just suggesting something that you might be able to do that’s non-confrontational I would definitely call it loud though, if you can hear it with headphones on.
I don't know if I hear it or feel it as I can't always hear the melody or talking (if TV) but if I am listening to my own music or watching my own tv with headphones in the bass comes crashing through and completely spoils whatever I am doing as it's out of synch. I find it way worse when I'm trying to watch something than if I'm just sat in a quiet house. They watch a lot of Marvel and action movies so the bass scenes are almost constant and dramatic when something exciting happens or there is a backing track.
Sounds like their speaker system is touching the floor when it shouldn’t be and causing vibrations. They need to get a vibration absorbing stand for it or turn it down.
Husband spoke to the wife/girlfriend over fence this morning and she asked if it was better so he said it yes it was last night. She said she agrees with us as it annoys her too and they didn't realise the tv had a setting to turn it down so they've done that now (they do know because they said they'd do that over a year ago). All sounded positive except it's back to exactly how it was yesterday now. They have awful arguments where he sounds like a right lovely person towards her so I guess we know where the problem lies.
It's a shame you can't bring them over to show them what you can hear. Obviously not a good idea at the moment.
Thanks so much for reminding me of this. The Johnny Cymbal version used to be my go-to request at parties, but for some reason I've not listened to it for years!
If they’re younger than you and your husband you may be able to play a tone that only they can hear. Like those things outside the bus station in town
if it annoys the girlfriend then lovely boy must be playing it loud primarily to annoy her not you? - a weird form of control?