
Hi Raymond. The best time is when things are calm, not mid-incident, ideally early evening on a weeknight or Saturday afternoon. Knock, smile, and keep it short and specific. Try something like: "Hey, I'm Alex in 3B, up at 6 for work, would you mind keeping music down after 10, especially the bass?" Offer an easy fix on their side and a way to reach you: "If it helps and moving the speaker off our shared wall can cut the thump, and here's my number."
If it happens again, a quick knock the next day or a short text works better than a midnight confrontation, and keep it to one line. Low cost things on your side that help a lot are a white noise app on your phone at low volume near the door, silicone earplugs such as Mack's for about five bucks, and sliding your bed six inches off the shared wall. A rolled towel at the door and a thick throw or bookcase on the shared wall can knock down bass that sneaks through gaps. Keep a simple log of dates and times for a week so you have specifics. If it keeps up, ask the landlord to send a building wide reminder about quiet hours or city noise rules rather than filing a formal complaint, and share your short log.