Questions & Answers

Ground loop from switcher

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asked Sep 9, 2020 in StudioLive Series III by geoffreyhearn (150 points)
edited Sep 9, 2020 by geoffreyhearn
Update 3:20 pm 9/9/20: I've narrowed the culprit of the ground loop down to the ATEM Mini Pro. Still trying to find out how to kill it.

I searched and found similar questions, but not the same:

I have a Studiolive 32 and run both FOH and livestream audio simultaneously.  I've been using USB audio out. The sound is far superior to XLR through the camera (which is what I was doing until a month ago), but the audio goes out of sync with video. So I'm trying to find the balance between over-working myself re-syncing and having better audio quality.

The issue I've run into is that now my XLR out (matrix mix out) has a loud high pitch hum. It sounds like a grounding issue, but I've never had issues with it before and I haven't moved the board. I've tried stereo and mono mix. I don't hear it on my headphone monitors or through digital routing. I've tried switching XLR ports and it still occurs.  Same cord, camera, soundboard, and port as I was using before without the hum.

I've tried turning the volume up at the board and down at the camera and vice-versa. I've also tried to rout the audio directly through the switcher (BlackMagic ATEM Mini Pro).

TLDR:  How do I remove a hum from XLR out?

Thanks in advance!

1 Answer

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answered Sep 10, 2020 by jonnydoyle (403,360 points)
Best answer
Find where the hum is coming from and fix at source. Could be an input. Either that or place a DI box between the mixer and external equipment and lift the ground on the DI box.