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Audio Levels - Fine When Recording / But Low Levels in QT-FCP

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Brian Broz

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Hi,

Im on a shoot in Mexico and the audio and levels seem fine on the camera (direct into camera w upgraded audio from a shotgun +48v). Peaking at -12db or so...but when the editor plays back the quicktime proxy in FCP the levels are peaking at -30db.

Has anyone experienced this?
Help!

Brian Broz
 
Brian Broz said:
Hi,

Im on a shoot in Mexico and the audio and levels seem fine on the camera (direct into camera w upgraded audio from a shotgun +48v). Peaking at -12db or so...but when the editor plays back the quicktime proxy in FCP the levels are peaking at -30db.

Has anyone experienced this?
Help!

Brian Broz
Click to expand...

Yes.
In our situation, the audio channels in FCP were found to be out of phase.

Not sure where that occured as they were recorded at the Red in phase.
At any rate, disable one of your audio channels in FCP and see if that corrects your level.
 
Thanks Mike!

Will check that out.
Cheers,

Brian
 
Hey RED, what is the deal with the low audio levels in NLEs?

Hey RED, what is the deal with the low audio levels in NLEs?

We have the exact same problem. The levels look great on the camera, but are very low in FCP.

However, the audio-out-of-phase explanation can't possibly be correct. FCP doesn't care whether levels are in-phase or out-of-phase. That would only make a difference during playback if one were playing two out-of-phase tracks simultaneously.

The levels are the levels. Each track is recorded independently of the other. When we look at the individual tracks, they are extremely low in FCP. . . almost flat line! And since, in our case, we only recorded one audio track, it can't be an out-of-phase situation internal to the camera that was somehow recording a combined signal to the one track.

My personal suspicion is that the RED's meter is grossly incorrect somehow. I would definitely like to see RED's thoughts on this important issue.

Stephen
 
We get low levels in FCP also, although it hasn't proved to be a problem. Record 4 shotgun mics directly to camera (with 48 Phantom power on). I set a mic level of about 40dB to make sure I get a reasonable signal in FCP/STP. At this setting the RED meters consistently push into the yellow bars. Sound quality is excellent.
 
Stephen Pruitt said:
My personal suspicion is that the RED's meter is grossly incorrect somehow. I would definitely like to see RED's thoughts on this important issue.
Click to expand...

I agree. The audio levels from RED are near flatline in FCP, but audio from, let's say the HVX200 match almost exactly neck and neck with camera/FCP.
 
Just received my upgrade and ran a line level test. -20 tone from Sound Devices, line input to Red at 0dB. (the other option is +10)

tone hit the hash mark, maybe a touch hot. Audio was fine as long as I did not exceed -20 out of the mixer. Not much headroom above that. Got pretty crunchy if there was any red on the Sound devices meter, which corresponds to yellow on the Red Camera meter.

The test tone reads out as -16 in FCP, which is -28 below unity. Sounds ok.

Still can't power my Neumann mics directly from the Red, so haven't tested the mic level input. Will try sending mic level from mixer.

conclusion:

It appears the Red runs at 0dB input level (as opposed to the usual pro level of +4dB or consumer -10dB) so be gentle when sending from a +4dB mixer.
 
Reference Level

Reference Level

Our line input reference level is 0dBu / 0.775 volts RMS / -20dBFS. Use 0dB Input Level for that.

In addition there is a +10dB Input Level setting for use with -10dBu (consumer) line level inputs.
 
Can I ask Stuart, which pro standard document did RED make it's decision on. Is it US installations? Or is there an other reason?
+4dBu = -20dBFS = 0dBVU SMPTE and +4dbu = -18dBFS = 0dBVU for Europe EBU R68
 
Stuart. . .

Why are our levels, which look great in camera, look so puny on import into FCP??? Several of us are having this difficulty.

Thanks.

Stephen
 
FCP audio meters

FCP audio meters

Why are our levels, which look great in camera, look so puny on import into FCP??? Several of us are having this difficulty
Click to expand...

That is a good question. Have you had this experience with other NLE systems or just FCP?

In our opinion, the level recorded to media is correct, as indicated by playback through our meters and on the analog outputs.
 
Levels

Levels

Can I ask Stuart, which pro standard document did RED make it's decision on.

+4dBu = -20dBFS = 0dBVU SMPTE and +4dbu = -18dBFS = 0dBVU for Europe EBU R68
Click to expand...


O.K I'll restate this. Our line input reference level is 0.775 V RMS.

Whatever you wish to call that in "dB" ...


For right or wrong, what we say is 0.775 V RMS = 0dBu = -20dBFS


So its possible we have our terminology mixed up between 0dBu and 0dBVU..

..please tell us if that is so, and we'll be happy to correct our documentation to reflect that.
 
FYI. Wendt X3 mixer. 0dB tone from the mixer just lights the yellow in the camera.

In FCP, reads out as -14, -26 below unity.

Ran some dialogue tests. It seems you've got about 6 dB headroom after the camera meter hits yellow.

I can not run the Wendt, or the Sound Devices, at optimum levels. Normal output distorts the Red. If I run those mixers conservatively, it sounds fine. Since it's digital, the noise floor is low. Not ideal, but usable for now. Why not +4dB ????

Conclusion: Be very careful with the Red one meter. Keep it green. Yellow is dangerous and red is cooked.
 
Levels

Levels

FYI. Wendt X3 mixer. 0dB tone from the mixer just lights the yellow in the camera.

Ran some dialogue tests. It seems you've got about 6 dB headroom after the camera meter hits yellow.

I can not run the Wendt, or the Sound Devices, at optimum levels. Normal output distorts the Red. If I run those mixers conservatively, it sounds fine. Since it's digital, the noise floor is low. Not ideal, but usable for now. Why not +4dB ????

Conclusion: Be very careful with the Red one meter. Keep it green. Yellow is dangerous and red is cooked.
Click to expand...

I also posted this on the other thread -

That suggests your input level is too high or you have +10dB gain enabled for line input.

It shouldn't be lighting up yellow, as you are correct when it changes from green to yellow its indicating about 6dB of remaining headroom before clip...

When I run my Sound Devices 302 (I don't have it with me unfortunately) at -20dBFS, my camera indicates its hitting the witness mark right on the nail.....


What build of firmware are you on?

Is it possible you have +10dB Input Level gain enabled on the RED ONE?

There was a bug in earlier Builds (17 for example) where that was the default setting when the camera turned on....
 
It doesn't make a bit of difference if we are using our mixer or not. Regardless if we use the RED's preamp or go out from our 788T, if our levels are fine on the camera, we get next to nothing in FCP. I mean, these levels are practically flat-lined. If we raise levels into the camera, we clip. If we pull the levels directly from the 788T, we get great levels in FCP.

This was never an issue with our HVX-200. But it is a constant battle with the RED. . . just because it looks good on the meter doesn't mean that it is good. My editor keeps saying things like "look at these audio levels. . . there's almost nothing there." Unfortunately, since the noise floor is fixed, this means we don't have a lot of ability to raise the levels in post.

Anyway, it is frustrating, and a lot of us are facing this situation. And it has nothing to do with the +10 line level. We don't have any other NLE to toy with here, so I can't say if it is a FCP issue or not.

Thanks.

Stephen
 
Audio Levels

Audio Levels

This does not sound (no pun intended ) right.

When you "import directly from the 788T" what method does that imply?

What settings do you have for audio on the FCP - i.e mono or stereo?

What Build of RED ONE software are you using?
 
Let me clarify. . . when I import the files directly into FCP from the 788T (recorded using a double-system and bypassing the RED entirely), the levels are perfect. No issues.

In our case, we're using Build 18 just now. I'm not sure what the other folks experiencing this problem are using.

Audio is imported into FCP as mono tracks. Sometimes one, sometimes four, but never stereo, per se.

Thanks.

Stephen
 
I am also using build 18. And my tracks import sometimes as mono, sometimes at multiple tracks. It's always magic with what audio I get, but it IS consistently virtually silence until I raise the levels and introduce noise.
 
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