Answers.Body: <h2>tl;dr</h2>
  <p>Make sure none of the SDI outputs of the ATEM are routed back to its inputs.</p>
  <h2>Talkback feedback loop</h2>
  <p>The ATEM uses SDI channel 15 and 16 for talkback. If you route one of your SDI outputs to the SDI inputs (either directly via a simple SDI cable or trough a system of devices like record/playback devices) you will get a feedback loop that causes this high tone.</p>
  <h2>Possible solutions</h2>
  <p>The simplest solution is to break the loop by removing the cable/devices causing it. Obviously this way you will loose the functionality you tried to add trough it, like having M/E 1 PGM as one of your inputs so you can use it as an input on M/E 2, 3 or 4, so if you would like to keep the loop without the noise you have to deembed or redirect the audio from channel 15 and 16. You can use something like the <a href="https://decimator.com/Products/MiniConverters/MD-HX/MD-HX.html" rel="nofollow noreferrer">Decimator MD-HX Cross Converter</a> that can reroute SDI audio channels.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-24T15:54:53.443Z
Answers.LastActivityDate: 2020-07-24T15:54:53.443Z
Answers.UserDisplayName: totymedli
Body: <h2>Setup</h2>
  <p>I have a Blackmagic ATEM 4 M/E and one of their studio cameras. I have a headphone on the camera and an active speaker on the ATEM so I can hear talkback.</p>
  <h2>Problem</h2>
  <p>There is a super loud whine/tone/whistle/noise. It is similar to a <a href="https://www.szynalski.com/tone-generator/" rel="nofollow noreferrer">1kHz square tone</a>. Even if I set volume to minimum it is hearable.</p>
  <h2>What I tried</h2>
  <p>I tried to disconnect the cable going into &quot;SDI in&quot; from the camera. The tone is still there but only in the ATEM so the source has to be the mixer. I added a mic to the talkback XLR input but it can't be heard. I also tried to add a sound mixer to this same XLR input and even if I set volume to the max it can be barely heard but the tone is still super loud compared to it. What is the problem?</p>
  
Tags: <blackmagic><noise>
Title: What causes a loud tone/noise in Blackmagic ATEM talkback?
UserDisplayName: totymedli
ThreadText: # What causes a loud tone/noise in Blackmagic ATEM talkback?
  
  (Asked by: username_0 on 2020-07-24)
  
  ## Setup
  
  I have a Blackmagic ATEM 4 M/E and one of their studio cameras. I have a headphone on the camera and an active speaker on the ATEM so I can hear talkback.
  
  ## Problem
  
  There is a super loud whine/tone/whistle/noise. It is similar to a [1kHz square tone](https://www.szynalski.com/tone-generator/). Even if I set volume to minimum it is hearable.
  
  ## What I tried
  
  I tried to disconnect the cable going into "SDI in" from the camera. The tone is still there but only in the ATEM so the source has to be the mixer. I added a mic to the talkback XLR input but it can't be heard. I also tried to add a sound mixer to this same XLR input and even if I set volume to the max it can be barely heard but the tone is still super loud compared to it. What is the problem?
  
  **Tags:** blackmagic, noise
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2020-07-24. Score: 2 | Accepted answer
  
  ## tl;dr
  
  Make sure none of the SDI outputs of the ATEM are routed back to its inputs.
  
  ## Talkback feedback loop
  
  The ATEM uses SDI channel 15 and 16 for talkback. If you route one of your SDI outputs to the SDI inputs (either directly via a simple SDI cable or trough a system of devices like record/playback devices) you will get a feedback loop that causes this high tone.
  
  ## Possible solutions
  
  The simplest solution is to break the loop by removing the cable/devices causing it. Obviously this way you will loose the functionality you tried to add trough it, like having M/E 1 PGM as one of your inputs so you can use it as an input on M/E 2, 3 or 4, so if you would like to keep the loop without the noise you have to deembed or redirect the audio from channel 15 and 16. You can use something like the [Decimator MD-HX Cross Converter](https://decimator.com/Products/MiniConverters/MD-HX/MD-HX.html) that can reroute SDI audio channels.
  
  
  ---
  
  