Hyperdeck's Mysterious Audio Recording Ability.

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Gabriel Ng

  • Posts: 18
  • Joined: Tue Jan 10, 2017 10:43 am

Hyperdeck's Mysterious Audio Recording Ability.

PostSun Jun 28, 2020 12:41 pm

Hi all,

This phenomenon has gotten my scratching my head in disbelief. I thought that 32-bit audio recording was introduced by Sound Devices and Zoom. But my Hyperdeck exhibited this behaviour in its audio recording which I'm hoping to get an explanation.

We record our live video feeds from an ATEM 4K 1 M/E. Audio from our sound desk is send into the ATEM. Recording format is PRORES LT.

I took back the recordings in FCPX and when I looked at the waveforms, it was extremely low for spoken word. It was virtually flat!

However, when I increased the gain by another 20dB, I managed to recover the audio with no added noise at all!
It was absolutely clean and usable. I was hoping some one could explain to me how audio is recorded in the hyper deck that would allow such behaviour.

Thanks in advance!
Attachments
Screenshot 2020-06-28 at 8.37.58 PM.png
Audio after boosted with gain and some compression
Screenshot 2020-06-28 at 8.37.58 PM.png (564.93 KiB) Viewed 332 times
Screenshot 2020-06-28 at 7.26.33 PM.png
Original audio file
Screenshot 2020-06-28 at 7.26.33 PM.png (603.26 KiB) Viewed 332 times
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Gabriel Ng

  • Posts: 18
  • Joined: Tue Jan 10, 2017 10:43 am

Re: Hyperdeck's Mysterious Audio Recording Ability.

PostWed Jul 01, 2020 1:26 am

Hey all,

Does anyone have any input on this? I’m curious as to know how this works.
Thanks!
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Dave Del Vecchio

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Re: Hyperdeck's Mysterious Audio Recording Ability.

PostThu Jul 02, 2020 5:00 pm

If you are taking the SDI or HDMI video output from the ATEM into the HyperDeck, then any analog to digital conversion of the audio has already happened by the time the audio gets to the HyperDeck. I believe the ATEM outputs 24-bit / 48 kHz audio embedded with the video output, so the HyperDeck is simply recording the digital audio it is receiving.

So there's not any magic happening within the HyperDeck here. 24-bit audio does provide a decent amount of dynamic range though, which may be sufficient for boosting the audio in post.
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Gabriel Ng

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  • Joined: Tue Jan 10, 2017 10:43 am

Re: Hyperdeck's Mysterious Audio Recording Ability.

PostSat Jul 04, 2020 3:22 pm

Dave Del Vecchio wrote:If you are taking the SDI or HDMI video output from the ATEM into the HyperDeck, then any analog to digital conversion of the audio has already happened by the time the audio gets to the HyperDeck. I believe the ATEM outputs 24-bit / 48 kHz audio embedded with the video output, so the HyperDeck is simply recording the digital audio it is receiving.

So there's not any magic happening within the HyperDeck here. 24-bit audio does provide a decent amount of dynamic range though, which may be sufficient for boosting the audio in post.


Thanks Dave for your response. Appreciate the insight!

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