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Hyperdeck 12G Feedback issues

PostPosted: Sun Feb 25, 2018 4:41 am
by stephyuji
I have a ATEM 2m/e, an ultrastudio, and 4 hyperdeck 12G's in my new setup. I record at 2160 24fps. My issue is with the hyperdecks. If I input a signal from my ATEM, I can record without problem. However, in my situation I want to output the signal from the hyperdeck back to the ATEM for playback monitoring purposes.

When I tried this I found the following:

(1) Anytime input and output cables were plugged into the ATEM simultaneously and I pressed the input button on the front panel I found that the hyperdeck would begin to feedback. The feedback would start sometimes immediately or sometimes after a few seconds—it was a low hum that would start to squeal. If removed the output cable or deactivated the input button the noise would immediately stop. Despite this behavior the ATEM would display the signal from the hyperdeck.

(2) This behavior only held true if the output cable was plugged into one of the loop out/out 1/out 2 ports. The feedback would not be present when I plugged the output cable in the monitor out port. But the monitor out port appears to have a default video setting which is not the same as the input signal—so no signal on my ATEM!

This NOT an audio feedback issue. The feedback happens on ALL my hyperdecks 12Gs whether they have a live input source or not—just the mere fact that input and output cables are plugged in simultaneously creates the hum. I have swapped my cables. No change. I thought it might be an interference issue with powercords—but the situation does not change even with just the ATEM and hyperdeck in my setup.

What am I doing wrong? Is plugging the output back into the ATEM somehow not correct? If so, how can I monitor my hyperdecks without a dedicated monitor for each hyperdeck?

Re: Hyperdeck 12G Feedback issues

PostPosted: Sun Mar 29, 2020 4:33 am
by Linden deCarmo
I ran into this issue today trying to record our church service. If we're recording to the hyperdeck 12G and the monitor output is enabled on the hyperdeck output into the ATEM, there is a massive noise generated. I had assumed it was a feedback loop that the hyperdeck was in fact trying to record itself but now, based on your comments, I'm not sure.

Why is the hyperdeck sending an output signal to the ATEM when its recording? Is this an software bug or a hardware bug/limitation? Is there any workaround for this other than getting two hyperdecks (one for playback and the other for recording)?

It really does seem wasteful for our use case to have to get a second hyperdeck to avoid this feedback loop/issue.

Re: Hyperdeck 12G Feedback issues

PostPosted: Sun Mar 29, 2020 6:01 am
by MambaFiber.com
One of 2 things could be causing this...

The hyperdecks record/playback 16 channels of audio. Ch 1/2 are the ATEM audio mixer output, and Ch 15/16 carry the intercom audio used by BMD cameras. When you press the input button on the hyperdecks the input loops back to the output. The ATEM completes the loop back to the hyperdecks on the intercom channels, this is prob the issue. Fix by disabling Ch 15/16 Audio on the general tab of switcher settings in the ATEM software. The problem could also happen on Ch 1/2 if you have the audio input turned on and fader up for the channel the hyperdeck is plugged into on the ATEM. Fix this by turning off the audio fader.

I wish you could disable some audio channels on the big hyperdecks. You can select 2/4/8/16 tracks on the HDminis, it would be nice for all of the products to have similar features.

Re: Hyperdeck 12G Feedback issues

PostPosted: Sun Mar 29, 2020 2:57 pm
by Xtreemtec
I agree with Greg,

This is caused by loop back of the audio. Also BMD should allow to not Record Channels 13-14 & 15-16 which are the intercom channels of the newer Atems..

The intercom is to no Use to have on the recording. So why not chop it off??

Re: Hyperdeck 12G Feedback issues

PostPosted: Sun Mar 29, 2020 3:00 pm
by Linden deCarmo
MambaFiber.com wrote: Fix by disabling Ch 15/16 Audio on the general tab of switcher settings in the ATEM software.


We had talkback disabled so its not that.

MambaFiber.com wrote: The problem could also happen on Ch 1/2 if you have the audio input turned on and fader up for the channel the hyperdeck is plugged into on the ATEM. Fix this by turning off the audio fader.


This probably is the issue. We need to play from the hyperdeck for recorded clips and its very easy to leave that channel unmuted (happened to me yesterday). We had massive feedback on the livestream when the recording started because I had played a test clip before the service started and forgot to mute that channel.

We really need an mechanism to prevent the feedback loop if the channel is left unmuted when recording starts. Any thoughts/suggestions for a workaround would be appreciated.

Re: Hyperdeck 12G Feedback issues

PostPosted: Sun Mar 29, 2020 6:14 pm
by MambaFiber.com
Set the audio fader for the Hyperdeck to AFV instead of ON. Leave the fader pushed up. In this case the Hyperdeck audio will only be heard when the Hyperdeck is switched to the PGM buss. When the Hyperdeck is taken off PGM the audio will be turned off as well.

Re: Hyperdeck 12G Feedback issues

PostPosted: Sun Mar 29, 2020 10:18 pm
by Linden deCarmo
MambaFiber.com wrote:Set the audio fader for the Hyperdeck to AFV instead of ON.


Thank you Greg. AFV solved the feedback loop.