I recently ran into an issue with FW version MSPK v1.39. When going into Concert Mode, the latency from the video on my laptop to the audio in the speakers varied by several hundred milliseconds. When starting the video, the latency was around 433ms and after ten minutes the latency had dropped to 133ms.
I used the following YouTube video to analyze the problem: https://www.youtube.com/w...jRA1HBZhJ18&t=634s
After some messing around with EEPROM settings, I found that if I set the A2DP Latency for Multi-Speaker mode to zero, the video-to-audio latency was constant. See attached image.
It seems that there may be a firmware issue with latency variance in Concert Mode.