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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Recording line level audio

When I take a 702T Sound Devices, go into the recorder's menus and select -20 dBFS on 1Khz tone and output from the TA3 line out to the TA3 line in on the RED One the resulting playback in FCP is -20 dBFS.

On my 302 Sound Devices mixer the 1K tone at 0dBU is just slightly hotter like -18 or -19 dBFS when played back but really close to -20. You have to make sure your camera line level is set at 0dBFS and not +10 under the Video/Audio/Line.
 
I too am having this problem with a newly upgraded audio board.

On a shoot this weekend we blasted the line level with a Mackie Mixer until it metered just a bit under peaking.

Playback in camera seemed to sound fine.

But when played back in Final Cut Pro or Quicktime, the audio is whisper quiet. The FCP audio meters barely get above the -30 marker.

Yes, I am using the correct cable and yes my line level is set to 0db.

Thank you.
 
I ran into this recently as well when using a feed from a Shure Mixer on set. I'm about to run a little test and will confirm for everyone what the deal is. Be back in a little bit.
 
We are also experiencing this problem on our upgraded camera. We've verified all of the above and are still over modulating.
 
We saw this on a recent shoot as well and ended up going right to the external decks and bypassing the camera altogether. Not my first choice as now I have a bunch of added cost to make sure all our audio is lined up when we post when I should have at least had reference on camera. When the audio got into FCP the levels were to quiet to be usable.

We also had the studio's Sound Devices mixer and thank god we decided only to use the on camera sound only as reference (we went off the outputs on the deck to the mixer, then out wireless to the camera).

While I'm not a sound guy and I don't pretend to play one on TV, it would be REALLY nice of someone would actually do some work on this area of the docs, our sound guy (a veteran who just finished work on an Academy Award winning film) can feel a little better about working with a camera system we're otherwise pretty comfortable with. His words were precisely, "these docs are totally worthless."

This shouldn't be such a mystery, but as with most things, it boils down to poor technical documentation (I have to agree with our soundman), and relying on a web forum to fill the gaps. That's a dangerous choice in my opinion as it's not accessible in the field all the time, and is a poor (or worse, misleading) reference in a pinch when you just need to know one little technical detail in a hurry (while a producer is breathing down your neck on set wondering when he can get the take).

While it's true these things are best resolved in pre-production, there are always little questions that arise on set (why my ASC manual is always in my kit when I am filming, I don't have hyperfocal charts for every format dedicated to memory and I can't expect the soundman to have the technical details of every camera system in his memory banks either).

To be blunt, there are too many morons on the internet trying to prove their intelligence to the universe to rely on web forums as a form of technical documentation. I think this is one of the little areas Red can focus on to improve the customer experience with their products (which we otherwise love).

The forums are a nice thing for immediate support and for building community, but they will never replace proper technical manuals or documentation (this includes the software products as well which really suffer in this area).

I think while the camera probably does the right thing, it would be nice if some effort was put into making some extensive updates to the documentation and getting that out into everyone's hands asap.

J
 
upgraded audio board.. all kinds of issues..

tone peaking...
evf flashing when recording audio
(think i figured the last one out.. happens with NON RED xlr-xlr mini cables...
or when recording 2 channels.. dont know which one yet)
 
This is what I got from my trusted audio guy. I hope that this helps clarify and I hope it's all accurate. Please comment on inaccuracies as we are going into a 4 day shoot Friday.

"The 0db level on the red is neither -10dBv (consumer line) nor is it +4dBu (professional line) it is 0dBu (another line level that appears on some mixers like a Mackie, and also on DVCPro decks). This level is in-between the other two line levels. So… sending a tone at 0dBu out of, say a Mackie which will show tone at 0dBu on the meter, should come up to -20dBfs OR whatever the RED is set up to receive that 0dBu signal. Other manufacturers use -16dBfs, -18dBfs at 0VU reference level on a +4dBu or 0dBu line level.

It is important to remember that the dBfs scale does not translate directly to digital meters showing VU, and those VU meters can be set to any of the three line level signals (+4dBu, 0dBu, -10dBv). Also, there is not 14dB difference between +4dBu and -10dBv, nor is there 10dB difference between 0dBu and -10dBv. They are different scales based on different voltages. It is advisable to use a 0dB scale like on a Mackie to check your tone and where it comes up on the RED."
 
Considering we have a 2 camera shoot for a never to be repeated event in just three weeks, using two RedOne's with the new revision audio board, it would be of some interest if someone from Red would actually make a comment on this.

Our sound guy called me again today asking if there had been any official word on this.

Seems making some clarifying additions to the manual would be a really good step in the right direction for a lot of us who would like to take better advantage of the improved sound capabilities.

Not trying to be an a$$, but we can really use some official clarification here, and not just in the forum, I'm taking about actual documentation I can put in the hands experienced crew (who have what I think is a justifiable beef with the extent of documentation on the sound subsystem for the camera).

Jim... anyone?

Cheers,

J
 
This thread has gone awfully quiet but seems to be lacking resolution. Has anybody received any answers from the powers-that-be? Or figured out a solution on their own? I submitted a tech support request to RED but never received a reply. We really need an solution to this issue.

In summary, we continue to see line levels that are much hotter than they should be, (levels on our Mackie mixer are barely registering but are very hot on the camera) and even if we turn the mixer way down to compensate, the audio imports distorted with clipped waveforms, even though the meters in the camera never clipped. I've triple checked and the camera is set to line level (0db).
 
Interesting thread, thanks for the link. But at least in my experience, the issue seems to be more than just insufficient documentation. No matter what we do, (including trying several different mixers), line level audio is distorting in our camera, even at very low levels.
 
Agreed, there may be other issues at play here. But until we have technical specifications and documentation we're not going to know what we need to do to test accurately.

Once you have the docs you should be able to create two or three valid test cases and know, with near certainty what your results will be.

If they differ from your expected result then you can say to the engineers, I did this and I expected this result, but got this instead; why?

Otherwise you're just tossing darts right?

I just want to be able to generate a suite of test cases record the results after confirming correct operation.

This is important for any production system you may be using in the field. If something starts behaving badly or outside of the expected operational parameters you have a handful of (usually quick) tests you can perform to confirm your suspicion. You'll know if you do x, you should get y result. If not, you got a problem, and hopefully you know where.

J
 
Jeremy Neish said:
Interesting thread, thanks for the link. But at least in my experience, the issue seems to be more than just insufficient documentation. No matter what we do, (including trying several different mixers), line level audio is distorting in our camera, even at very low levels.
Click to expand...

I agree. To be honest, if I had the opportunity I'd take my old sound board back. There may be noise on phantom, but I had a custom cable made where I took the phantom out of one channel, but the actual audio out of a different channel. Result clean sound. Now, as discussed, distortion/seeming over-modulation even though line levels were in range and levels when imported into FCP are -12 or less.

I'm sorry, but this needs to be fixed.
 
I think part of the the problem is that an analog mixer at 0 dBu is not the same as sending a -20 signal from a digital device like a Sound Devices recorder which you can set the menu at a specific tone level.

If I send a signal from a digital source at -20 dBFS, out at analog +4 line level from a 702T it hits the right hash mark. It is a simple TA3 to TA3 connection.

If I send a 0dBu 1k reference from my 302 Mixer it is slightly hotter. I am sure every analog mixer is going to send a different level. Early on back in build 12 when audio on Red was new, I was on a shoot where a PSC mixer was sending a level that had to be 30db hotter than my 302. And that was supposedly standard line level. So I know mixer to mixer the 0 dBu tone will vary, it isn't the camera.

If you send a known digital to analog line level signal like the first example (the 702) it will record and open up in FCP where it should. The analog source can be within a range. Analog mixers are all over the place. My 302 comes really close but it is not as exact as using the 702T.

And as to the Mackie references in this thread do they send a 0dBu 1k tone? I know none of my Mackies send tone, but they are older.
 
Brian Ferguson said:
If I send a 0dBu 1k reference from my 302 Mixer it is slightly hotter. I am sure every analog mixer is going to send a different level. Early on back in build 12 when audio on Red was new, I was on a shoot where a PSC mixer was sending a level that had to be 30db hotter than my 302. And that was supposedly standard line level. So I know mixer to mixer the 0 dBu tone will vary, it isn't the camera.
Click to expand...

Thanks for your explanation. Forgive my ignorance since I am not a sound person. I have a Sound Devices Mixpre which I think it should be very similar to the 302. So do you think it would be able to get good sound after the soundboard upgrade? So how do you do it? Because you can't adjust in the camera. When in Line mode, you can only put 0db or +10 Db. I guess since you are saying that the 302 comes a little bit hot, you will have to adjust in the master volume in the Mixpre and have it always out a little lower than what it should. But that is not very precise and I bet a sound guy would be quite annoyed. How much lower should he go before it peaks?.

Thanks
 
Sound Devices and the Red

Sound Devices and the Red

Hello all,

I'm a sound guy who is new to the Red. I have a feature coming up in a week that I will be required to mix to the camera for for the on set audio. I have heard a million horror stories with this cameras audio section. I have pushed for a dual system recording and for once production listened to the Audio Department as we will be renting a 744t. My original plan was to record the isolated tracks on the 744t and record the mix to camera, but readin all of this I think I am having second thoughts about this decision.

I have noticed alot of people bringing up the 302 mixer. I own one along with a 442 as well. I've made a point of learning everything I can about the equipment I use. This has led me to believe that those of you who have a 302 mixer are not taking full advantage of it's features. If you are getting levels at the camera that are too hot at line level you do have the option to attenuate the output of your 302 from within the menu of the mixer. If it seems hot than lower the output of the mixer in the mixer menu by the amount that seems best.

Another Sound guy I recently worked with mentioned working with the Red and said that the best audio he has gotten out of that camera was by setting the nominal input level of the Red to mic level -20 db and using a -10 db level on the output of his mixer ( which is easily reached by both the 302 using the mixer menu, and the 442 by simply using the switches by the ouptut section of the mixer). Anyone using a mix-pre will need to use pads at the output to do this. Doing this would simply mean that you're driving the mic level inputs hotter than normal. He did this because going line level was too quiet. Which goes along with the too hot of a level on the meters. It seems to me that these new boards are not properly calibrated with the meters on the camera and thus the levels are off based on the way people set them up.

I will now be requesting a test with the camera that we are shooting with for this feature, as I do not want to jeopardize my career for someone else's vision.

If I find anything questionable or anything that works I'll post.

Thank You,

Jason Hemmerlin

PS- If this camera is supposed to revolutionize the non-linear video world and possibly replace the film camera, then why the hell did they bother putting an audio section on it. Leave the audio to the Sound Dept. and the video to the Camera Dept.
 
Red shold also take a hint from all of the other manufacturers out there and make the inputs switchable giving a choice of only mic or line level and then having a gain control that you can fine tune the levels with. It's been a standard way of setting up audio on cameras for years. If it ain't broke don't fix it.
 
Audio

Audio

Jason, that's exactly the way it works.

You can choose Line or Mic level, and each Mic level input has an adjustable pre-amp gain.

The only difference is on Line we don't give you adjustment. You set the levels on your mixer.
 
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