Unusable Audio

[Seth Iliff]

I recently sat down with a Hitler Youth survivor of the war and had her tell her story on camera. I was using a high quality lav mic running to Channel 1. The 48V phantom power was turned on for the mic and I believe Channel 1 was set to around -28 db. There was a significant amount of static in the headphones, but the audio was clear behind it. The static didn't show up on the levels on the monitor, and her voice levels were set well so they wouldn't peak. So I STUPIDLY assumed that it was just the headphones and it would be fine. All the other settings I tried weren't working. Of course I was way behind and running out of time to do the interview.
So now I have to redo the interview because what I was hearing in the headphones was, in fact, what I was capturing- stupid me.
When I did b-roll of a number of photo albums she had I unplugged the XLR from Channel 1. The same level of static showed up in these clips as well.

Lesson learned- testing exact equipment. But I didn't have this problem when I used a different mic (phantom powered) and was unaware of the problem with the phantom power with most mics.

Solution: don't use the camera's phantom power with this build.

[Andrew M.]

Don't use phantom power.
Test your setup before you go out and shoot.

All is perfect if you use external phantom power supply.

Yes, audio is unusable except for the tests, with phantom power as of now.

use keyword 'phantom' to learn more.

[Anders Holck]

Thoughts?

Always test your gear in advance?

[Adrian Van Rossum]

Not sure what lapel mic gear you are using, but our Samson lapel mic receivers take their own 9volt batteries, so phantom power is not required on these channels. Don't have our Red yet, but we pipe these receivers to our Canon XL1, Sony PD-150 and Sony Z1 with phantom disabled in every case.

[Brian Ferguson]

I have listened to more RED cameras than most people. If you hear a problem on headphones, take a sample and listen in Final Cut from the proxies. BEFORE you have a crucial shoot. But my experience is that if you hear something on professional headphones you have a problem in the recording. If you hear something on the headphones stop and trouble shoot it.

There are a lot of RED cameras that do not have this problem, it sounds like it might be a camera specific issue. I urge owners to test their audio inputs in all expected situations before they shoot. Record on flash or RED Raid and playback the proxies in Final Cut and make sure you know the process you are going to use - before working when the pressure is on. This is film making 101. Test your camera in every circumstance you think you are going to use before you are there. Preparation is way easier than a re-shoot.

Remember that if you are switched onto Varispeed you will not hear any audio as a troubleshooting caveat.

Test before and make sure you are ready! Test test test. When I was doing film A.C. work every film camera and every magazine in a good prep has been scratch tested to make sure that everything was good.

All users camera's should be tested before they are in the trenches to make sure all systems are good. The more technology the more that can go south, please check before you shoot.

Be Careful Out There!

briferg