Sound ?!

[Nils Ruinet]

There has been a lot of talk about build 12, but there is one major feature that hasn't been discussed so much : Sound !

Hasn't anybody tried it yet ?

I just had a look at the updated user manual, and the specs look very promising. 4 inputs, 24 bit, 48 khz, uncompressed. So even here Red seems to offer more than the competition.
Now it would really be interesting to hear what real sound guys have to say about it.

Also, I didn't find how the files are organized. Are the audio channels embedded in the R3D file (hopefully not), or are they recorded as separate files ? WAV ? AIFF ? Is the BWAV format supported (with timecode and other metadata) ?

Concerning the post workflow, do 24 bit files need to be handled differently than 16 bit files ?

Thanks,
Nils.


Here is a quote from Red's user manual about sound (page 11) :

Line input analog audio received via the min-XLR inputs is immediately digitized at 24 bit per sample at a 48KHz sample rate. Microphone level audio inputs are routed via an adjustable gain pre-amplifier before digitization, no gain adjustment is available for Line level inputs.

Reference Line Input level (0dB) is 0.775v. Microphones with an output sensitivity ranging between -30dB and -60dB can be accommodated by the pre-amplifier, which provides user adjustable amplification over the range of +22dB to +54dB with minimal signal degradation.

Due to the significantly higher precision and dynamic range of 24 bit sampling, input stage limiters or AGC’s are not provided by the RED-ONE camera. The digitized audio data can be considered as high dynamic range RAW sound information that is complimentary
to the high dynamic range RAW video information.

Just as linear response RAW video data is converted to REC 709 for metering, the linear response audio data is converted to Log Base 10 data for metering. A color coded 4 channel audio meter is provided in the lower section of the camera GUI. This information is visible in the RED-EVF, RED-LCD and HDMI (DVI) monitor outputs.

The goal for optimal quality recording is to place the audio reference level at an appropriate location in the digital range, providing sufficient headroom above the reference level to prevent clipping, while maintaining the sound quality of lower volume sources such as dialog.

A 0dB reference voltage level of 0.775V provides approximately 8dB of headroom above reference. Microphone pre-amplifier gains should be adjusted accordingly (i.e. 8dB lower)

e.g. With an Azden SGM X1 microphone rated at -41dB sensitivity, set the microphone
pre-amplifier to (41 – 8) = 33dB for optimal recorded signal quality.

 

[Elizabeth Lowrey]

I, too, am very interested in the audio on the RED as I'm not from a film background and will always do my audio via camera absent a compelling reason to do otherwise. The manual info sounds encouraging. Would sure be interested in impressions from audiophiles out there.

 

[Alexis Hanawalt]

Along with this, I've been wondering how/where people intend to mount microphones to the camera for doc work, etc.

 

[BASSAM MSSALATIE]

:whistling: very nice remmarkable note hope somebody test audio for us please..:weight_lift:

 

[Finner]

I can forsee capturing good sound with a red being very difficult due to no audio control pots on the camera. I think most will have to capture audio with a different device other then the camera.

 

[I Bloom]

I can forsee capturing good sound with a red being very difficult due to no audio control pots on the camera. I think most will have to capture audio with a different device other then the camera.

It seems designed to take the line off a mixer. Which someone can surely do. We do it anyway on cameras that have pots.

 

[Finner]

It seems designed to take the line off a mixer. Which someone can surely do. We do it anyway on cameras that have pots.

Yes thats clear I guess I should have phrased things better by stating that capturing sound without a dedicated sound man will be quite difficult. Also when using a dedicated sound guy anyway it is often easier to have him record to a DAT and save cables running to the camera.

 

[Nils Ruinet]

Along with this, I've been wondering how/where people intend to mount microphones to the camera for doc work, etc.

And also, are the fans quiet enough not to interfere with such an onboard microphone ?
I guess when it gets hot, you'll hear the fans ?

 

[Unwounded]

Are there audio adjustments you can do in the menus?

 

[Anders Holck]

Regarding the location of the Audio:

2) audio is recorded inside the R3D files

3) the only way to currently use that audio track is through the QuickTime wrappers

4) regenerating the QuickTime wrappers in RED ALERT will *remove* the audio tracks!! A fix for this is high on the todo list for January.

 

[Mark L. Pederson]

I'm on vacation so I can't test this stuff - but has anyone tried opening a .r3d file with audio in REDCINE and exporting a QT? Does the audio pass through? (to a self contained QT of an user selected codec)

 

[I Bloom]

Important to note though that the audio itself will still be in the R3D file. Just no longer referenced by the quicktime file after you update in Redalert.

Finner, I'm seeing mounting one wireless reciever on the camera that is feeding off the mixer. The purpose being mainly that dailies will have sound immediately for the director. Otherwise, I agree with you seperate sound is always better.

Funny thing is, a lot of field mixers aren't even ready to transmit 4 track audio even if they are taking 4 inputs. I wonder if the location sound industry is even taking notice of this. I haven't heard for example of a breakaway cable that feeds 4 mini XLR3s.

IBloom

 

[Mark L. Pederson]

The purpose being mainly that dailies will have sound immediately for the director. Otherwise, I agree with you seperate sound is always better.
IBloom

I am actually going to feed all original channels from the mixer to the camera on my next production. Hard disc recorder (Metacorder) as back-up ONLY and for when we can't be teathered. The reality is - MOST OF TIME you run cables anyway for an HD monitor. Cables on set with a good crew is not really an issue to me - especially if you always have BWF back ups anyway. Getting QT wrappers off the camera with FOUR separate tracks of audio which can be transcoded immedaitely is a HUGE deal as far as I am concerned - and I will use the hell out of it -

 

[Dalibor Fencl]

I am actually going to feed all original channels from the mixer to the camera on my next production.

What original channels you mean? I can hardly imagine any soundman be able to simultaneously control the levels of four channels.

 

[Mark L. Pederson]

What original channels you mean? I can hardly imagine any soundman be able to simultaneously control the levels of four channels.

MOST of the time you work with 4 or more channels on features. Typically, one is boom, the others are lavs - sometimes there is an ambient mic placed as well. Back in the day - before hard disc recorders I often had DA88 on set to get all channels recorded independently in addition to the stereo mixdown that was going onto DAT - I found it always saved me money in post and/or got me better sound.

 

[Anders Holck]

What original channels you mean? I can hardly imagine any soundman be able to simultaneously control the levels of four channels.

I guess you have to tell that to this guy:

Bourne Ultimatum by the way. Using 10 digital zaxxcom microports.

 

[Mark L. Pederson]

I guess you have to tell that to this guy:

Bourne Ultimatum by the way. Using 10 digital zaxxcom microports.

He is rockin' TWO Cantars!! That is awesome!!!

 

[Dalibor Fencl]

Lol. I see, but still, if there are all those Nagras and DA88, is it necessary to send four channels to camera? And again those channels have to be controlled by someones hands, am I wrong?

Edit: I mean those channels sent to camera.

 

[Elizabeth Lowrey]

I can forsee capturing good sound with a red being very difficult due to no audio control pots on the camera. I think most will have to capture audio with a different device other then the camera.

As in no knobs for controlling gain on mic inputs????

If not, what does this mean (quote from the manual)?

Line input analog audio received via the min-XLR inputs is immediately digitized at 24 bit per sample at a 48KHz sample rate. Microphone level audio inputs are routed via an adjustable gain pre-amplifier before digitization, no gain adjustment is available for Line level inputs.

How do you adjust gain on the "adjustable gain pre-amp" for a mic signal then? If you tell me it's only available in some menu where you have to hit plus/minus buttons, I'll try to remain calm.

If there are no external, physical audio controls (I haven't really studied the body of the camera and so never really looked for them), then it's essential IMO to have the camera able to accept audio over firewire so that some of the portable devices out there that can double as A/D converters and digital mixers can feed the audio to the camera without reconversion. (I use the MOTU Traveler, but there are a lot of other, even smaller devices that would fit the bill.)

ETA: I just looked at the connector diagram thread, and, of course, there are no firewire inputs, only USB.hmy:

 

[Elizabeth]

Are there a visual audio level meter in the camera menu display window?

I have seen no mention of this feature, so I am guessing not.