Using a field mixer with an XH-A1

[David Seguin]

On the last project I did, I had to use a field mixer with my XH-A1, but couldn't figure out what levels to set on the cam so I just put it on auto. The sound came out great from the mixer, but the auto level on the cam would delay slightly (as expected), and I would get clipping.
My question is how should I set my levels on the cam so that my sound guy can set the levels from the mixer without having to worry about the cam levels? Or do I have to play around with both levels until both combined give me the audio levels I want?

[Allan Black]

What mixer do you have?

[David Seguin]

Actually I'm not quite sure. It was my school's mixer. But the reason I'm asking (besides simple curiosity) is because I'm considering buying my own and I'm also going to have to use the same one again next semester (unless I buy my own first).

I've been trying to figure this one out for a while now. If I put auto levels on like I said, it takes a fraction of a second before it kicks in, and if I get any loud sounds I get a bit of clipping. If I put manual levels on, it might sound good coming from the mixer, but the levels might be too high or too low on the camera. So the only way I can think of fixing it is by setting the levels on the mixer and checking the meter, then matching those levels on the camera's meter. But then any adjustments made on the mixer would also need to be made on the camera, so it kind of defeats the purpose.

For the time being, the best I can do is plug the mics directly into the cam, and using an extra long headphone cable so my boom operator can hear what he's doing.

[Allan Black]

It'd help if you could find out what school mixer it was did it have XLR outputs?

The procedure is you adjust the mixer line output to the A1 line input with that set on MANUAL then don't touch it. Once you do that all mic level adjustments are made on the mixer.

Depending on how many mic inputs you want good mixers are made by ..
Camcorder XLR Audio Adapter/Preamp: Buy Direct and Save

Cheers.

[Robin Davies-Rollinson]

Ideally, you should have a 1KHz tone generator on the mixer. Send it at LINE level to the camera and then set the manual camera audio level to -20db (that's what we use for broadcast, but it could be -14 if you like)
All the level adjustments are then made on the mixer.

[Steve House]

Originally Posted by David Seguin

On the last project I did, I had to use a field mixer with my XH-A1, but couldn't figure out what levels to set on the cam so I just put it on auto. The sound came out great from the mixer, but the auto level on the cam would delay slightly (as expected), and I would get clipping.
My question is how should I set my levels on the cam so that my sound guy can set the levels from the mixer without having to worry about the cam levels? Or do I have to play around with both levels until both combined give me the audio levels I want?

Send 1kHz tone at 0VU from the mixer and adjust the camera input level controls so the tone reads minus 20dBFS on the camera's meters, then lock off the camera settings. Now the mixer's meters are aligned to the camera and all level control of the actual signal is done at the mixer, setting gain so the mixer meters hover around 0VU or a tad higher on dialog.

[David Seguin]

Wow. Sounds a lot more complicated than it probably is. Sorry, I'm kind of clueless when it comes to audio. I've only used my camera on one project so far, so I'm not completely familiar with all the audio settings. From the research I have done however, it appears that if I switch it from MIC to LINE it bypasses the camera audio levels. If any of you have this camera could you tell me if this is correct? Or did I completely misunderstand that? I completely forgot I even had that switch lol.

Oh, and thanks for all the help.

[Steve House]

I don't have that camera but I'm certain you are incorrect. Setting the switch to 'LINE' changes the input sensitivity but the recording gain controls still work normally.

The meter in the camera's viewfinder will have a mark at 20 dB down from full scale. All decent field mixers intended for pro use will have a tone switch that sends a standard level 1kHz tone from its output.(Tone might be missing from some bargain basement models. If you're shopping for a mixer and one that you're considering does not have a tone switch, that would be a good reason to reject it.) Set the camera to 'LINE', plug the mixer into the XLR terminals, set the mixer's output knob to the detent that marks unity gain, turn on the tone, and adjust the camera's recording level dials until the meter's indicator lines up with the mark. Place a bit of gaffer's tape on the dials to they don't accidently get moved as you shoot. When you turn off the tone and someone speaks into the microphone, setting the mixer's input faders so the mixer meters read between the 0 and +4 VU marks will have the camera meters reading peaks around -12dBFS which is pretty much the 'sweet spot' for speech.

[David Seguin]

Okay, I get it now. Thanks for being so patient with my inexperience lol. I realize you just pretty much repeated what you had already said in different words.

Unfortunately, I think the school's mixers are the "bargain basement" kind. But I'll make sure I'll keep that in mind while shopping for my own.

[Jay Massengill]

You can also buy a device like this one:
Gold Line Goldline GL-1K Phantom Power Tester & Test Tone Audio Test Equipment at Markertek.com
It will generate mic-level tone for use with mixers that don't have a generator built in.
It is also useful for a basic test of mic cables to make sure they are properly passing phantom power.

[Steve House]

There is a way to get tone on a mixer that doesn't have it built-in by using something called a "Tone Plug" so if you're stuck with a bargain basement mixer there is a work-around (as long as it has meters). Just FYI in case you have a future need and are stuck using the school's gear. Glad to be of help.