Find out the audio lag in Bluetooth speakers

I have Bluetooth headphones which have a sub-second but noticeable lag.

I usually offset it in MPC by -300ms which seems right but I can't be sure.

It also seems to differ depending on whether I use speakers, stereo headphones, or mono headphones.

How to know this lag more accurately?


I find this video very useful: https://www.youtube.com/watch?v=s_PbyRpKrRk

You can download it with https://yt1s.com

Keep an eye at the "0" number and listen the sound. Then adjust the offset in MPC.