Firmware 17 and audio

[Olivier Madar]

I made my first test with audio under firmware 17, and here are some problems :

When i want to play back a clip on the camera, i get a green screen in the EVF and a message audio_fault (quad HD mode recording ). When I put the clip in FCP, the sound is here, but I get the orange bar and lose the video (message : render). If i change the settings for the sequence in 1024x576 (I work with "M" quicktime reference file), i get the video, but playback stop immediatly for the audio. If I change the audio settings to 96KH, 24 bits, I get the green ligne on the audio clip, but it stops also when play back.
I think the audio is 96 KH 24 bits, but why doesn't FCP recognize it when i put the clip on the time line ?

 

[Olivier Madar]

New tests :

I uncheck the "Max" checkbox : it is the same : can't play back on the camera a clip with sound.

Go back to 4K 16/9 instead of Quad HD : can't play back on the camera, but the issue on FCP has gone. My settings are 1024x576 and 48KHz and it plays smoothly. So, in Quad HD mode, the playback is smooth in FCP if no sound with 960 large image file, but with sound, you go back to red bar.

In both (quad HD or 4K 16/9 ), I can't play back a clip with audio on the camera itself (I did not try under firmware 16)

 

[Andrew M.]

Do you have new audio board installed?

It is good question, what RED is using to record the audio:
48 Khz 24 bit?

 

[Olivier Madar]

Hi,

I don't have the new audio board installed. And I did not do this test before upgrading to firmware 17.
I use FCP 6.0.4
When i change the sequence settings in FCP to 24 bits 96 Khz, i get the green bar, so I suppose it is natively from Red a 24 bits 96 Khz signal. But When i drag the clip to the time line in a new sequence, FCP choose "only" 16 bits 48 KHz.

 

[Stuart English]

Audio

Audio

It is good question, what RED is using to record the audio:
48 Khz 24 bit?

That is correct.

 

[farroutpro]

Do you have new audio board installed?

It is good question, what RED is using to record the audio:
48 Khz 24 bit?

According to tests done by Sound Devices the audio records at less than 16 bit

http://www.sounddevices.com/notes/cameras/red-one/

 

[Pietro Impagliazzo]

According to tests done by Sound Devices the audio records at less than 16 bit

http://www.sounddevices.com/notes/cameras/red-one/

I see this review is quite old (Build 15 and no audio circuitry upgrade).

With the upgrades does this scenario gets changed?

:mellow:

 

[NateWeaver]

According to tests done by Sound Devices the audio records at less than 16 bit

http://www.sounddevices.com/notes/cameras/red-one/

That page gives a bit figure correlated to a SNR ratio, which has nothing to do with what format the audio is recorded in.

Regardless, there is now an upgrade that they have not tested.

 

[Brian J.M. Rytel]

Oh yes, audio specs

Oh yes, audio specs

That page gives a bit figure correlated to a SNR ratio, which has nothing to do with what format the audio is recorded in.

Real word equivalent of audio equipment also fall (fairly) short of the technical specifications. This evaluation is very in-depth, and uses some loose estimations to convey the technical ideas. Thus our example: the RED recorded audio signal with the original audio board, has a bit-equivalent dynamic range of 15.8 bits to headphones, and 14.8 bits to WAV. Dynamic range (DR) isn't the same as S/N, however they are related.

Also, Sound Devices doesn't specify here if the bits are "x bits out of 24" or if they represent the DR in a hypothetical bit-space. Which makes a huge difference mathematically.