Mysterious ~15 dB Audio Level Drops during YouTube Livestream

[jerrykrinock]

In our livestreams on YouTube, sometimes the audio will drop by about 15 dB, once or twice (in the latter case, making a total drop of 30 dB). This has been seen to occur 3, 6 or 20 minutes into a 60-minute program. Once dropped, the audio level will remain dropped for the remainder of the program. Of course this is not necessarily an OBS issue; it may be happening in YouTube. The drop is always coincident with at least a slight momentary tear in the video. The operator claims that they do not notice any change in the audio level meters on the computer after the drop, although I have yet to verify this with my own eyes.

On March 5, the level drop occurred at 18:50:40. The associated log file is attached. As you can see, nothing was logged at the time of the level drop. The nearest log entries are scene switches, one 20 minutes before the drop, and another 5 minutes after the drop.

Of course, we plan to do some testing and keep close eyes and ears on this thing from now on. But if anyone has experienced anything like this, your experience would be appreciated. We're not sure where to look.

Thank you.

 

[jerrykrinock]

I should have said that we are pretty sure that problem is not on our analog side. In addition to the operator reporting no change in level meters, the audio is tapped off our house sound via a Focusrite Scarlett 2i2, and there is no drop in the house sound. The analog is all stereo, and the drop occurs in both left and right.

 

[jerrykrinock]

Well, since I don't see a way to delete a thread or post in this forum, I shall explain my conclusion. I think the problem is just that we had a new operator who was hyper-sensitive to meters going into the red, over-reacted and reduced the the gain way too much. I also put some pretty aggressive compression on the plucked (string) bass. It makes the bass player sound way better. So, in addition to instructing operators, I think that, unless the bass player is a real pro at plucking uniformly, some compression should be used on a bass plucked with the fingers. It's very easy to adjust the bass to an appropriate level in the mix, then have clipping if the bassist gets too excited about a note or slips.