AIBU to mention noise to neighbours?

[JammyDodger16]

Lovely neighbours, no issues at all apart from a 4 night a week game habit. He plays it from around 8pm to midnight and we think it is something like Call of Duty, very rumbly.
It's not technically loud enough to complain to anyone but it's really getting to us. It's constant rumbling, bass and in a narrow terrace we feel like the room is vibrating.

We are happy to chat to him, lovely couple, but I don't want to say anything if IABU

What would you do?

Tell him to turn sub woofer down

We wondered if that's what it was. We think he has it under the stairs and it acts like a speaker and ricochets it across to our staircase (houses are mirror of each other)

Or suggest he gets some headphones. (Though then he will shout at the other players. )

You can usually turn the bass down. Just knock and ask and to turn down. Do you both own or rent?

We own, they rent.

I'm happy to mention it to him, just wasn't sure whether I really had any right to as technically it's not loud, just bassy

YANBU to mention it in a friendly manner, they may be completely unaware it impacts your home life.
If they then continue you WNBU to tell them to shut the fuck up!

Ha ha! I suspect they are completely unaware. I will mention it to him tomorrow. It's like torture!

Hang a rug on the wall. Will muffle the noise.

I can't fit a rug - tv and shelves in the way

He might not be aware that the sound travels so badly. If you're on good terms with them then sounds like there would be no harm mentioning it to them.