Korean church is having problems with their livestream again. After they purchased a new camcorder and a new mixer, there’s a pickup of a very noticeable noise in the livestream (which can be replicated at all times in video files recorded with OBS as well).

The current setup is:

Microphone -> wireless receiver -(XLR to XLR)-> Mixer -(1/4″ to RCA)-> Camcorder -(HDMI to HDMI)-> HDMI Capture Card -(USB 3)-> Laptop

The noise is bizarre. By turning it up high, we hear radio broadcasting (on one of the recordings, I heard announcers discussing Trump’s indictment from yesterday. I also heard radio ads, etc.) mixed in with constant buzzing noise at around -30 db. We have to amp up the volume +20db to hear the microphone voice, which bumps up the noise up to -10 level, at which point it becomes very noticeable.

My first instinct was the wireless receiver/microphone. We compared the noise level with the mixer’s wireless microphone channel on and off, and it does not impact the noise at all.

Just in case, we also listened to the Mixer’s monitoring output through a headset, and as far as we can tell, there was no noise there.

Then we tested recording from the camcorder (getting audio feed from the mixer) directly into an SD card, instead of passing the combined output through the HDMI. Nope, the SD card video file is clean.

Then we hit a wall. Is it even possible that any of the following components are picking up on radio noise?

  • HDMI cable connecting the Camcorder with the Capture Card
  • The Capture Card itself
  • USB 3 connection from the Capture Card to the Laptop
  • Laptop internals

I ran some google searches. People experiencing noise were adviced to standardize all audio-related frequencies on the computer to 48khz. No, we don’t have this problem.. I checked.

Another non-related issue is that we don’t know whether the laptop has any USB3 ports. None of them are painted blue. We have yet to check on that one. But it can’t be related to noise.

Then I found this bizarre report from the USB Foundation where USB3 can cause interference to wireless signals . If this can go one way, could it possibly go the other way too? It’s impossible to imagine, since the USB3 signal is digital. How is it even supposed to happen?? If there was any significant interference into the data being carried through USB3, the data would corrupt. It wouldn’t be a matter of “noise”.

Pastor is gonna run to Best Buy to buy an El Gato Capture Card but I have low hopes of this fixing anything.