Find out the audio lag in Bluetooth speakers

Question

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?

Answer 1

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.

Answer 2

Try recording a video with sound on bluetooth speakers with as much fps as possible, then also record a second video with regular speakers, then cut+reencode(avidemux is an option) the videos so they start at the same video frame and compare their audio wave (audacity with ffmpeg support is an option).

If you don't have a video recorder you could use a screen recorder solution (like obs) with a microphone, but this would add more variables so it might reduce accuracy.

The precision of the measurement will depend on your test video fps, recording device fps and screen refresh rate.

I believe it is possible that the lag varies because of bluetooth interference and/or hardware implementation specifics, you might need to do several tests to know this for sure.

Answer 3

I have the same issue with Win7, so I'm going to try this at home when I get the chance:

https://www.drivethelife.com/windows-10/how-to-fix-bluetooth-speakers-sound-delay-on-windows-10.html

This article suggests looking at drivers, interfering Bluetooth devices, using the Windows Troubleshooter, and a variety of other areas of interest. It's designed for Win10, but most of it should work for other Windows versions.

I always hesitate to download "driver managers", like this article suggests. The one's I have done in years past generally seem to be more like "advertising managers." At minimum, the website that shows technical knowledge to fix your computer by downloading driver files or dlls wants you to download it's software first. That always screams "malware" to me, so no thank you.

BTW, part of why changing the audio to -300ms is because the brain sometimes can meld the audio with the video it gets into a single "stream" of input, as long as the two are somewhat close to in sync (not the boy band, however). By getting the audio and video at least close, your brain does the rest.

https://blogs.scientificamerican.com/observations/time-on-the-brain-how-you-are-always-living-in-the-past-and-other-quirks-of-perception/

Do a Find on "auditory" to get to the relevant section.