Recording levels

Big ScareCrow

Big ScareCrow

Well-known member
I just got done shooting a 6min short. We had our boom mic running through a 4 channel mixer, then into my camera. Most the shoot, we kept the signal in the green. (sorry I don't remember the number) But going back in Post, it seemed my signal was a little low. It was clear, but a lot of work to bring up. And then I saw it, a great discovery, in the sound meter in FCP, my sound had more room to jump into the yellow.

Now to my question, Should I strive to keep my signal in the yellow on my mixer, or can it spike just a little in the red. From my experience so far, spike into the red, is a no go, depending on exactly what sound is being captured. (i.e. low or high pitch).

So, if anyone could tell to go into the yellow, or keep it in the green, or even to spike a little in the red, it would be most appreciated.

Crow
 
It depends on the relationship between the levels of the mixer and the camera. If you calibrate the mixer and the camera to match clipping points, then you can know what to set your mixer at. Without doing that it is all arbitrary. You want the signals to bounce up above -12 in the camera, but not much higher. You want the limiters in the mixer to kick in before the camera gets to red. What mixer are you using? Does the manual say anything about this?
 
I hope I'm spelling this correctly, it's a beringer. Now when you talk about -12 on the camera, where exactly is that. I know that when the signal peaks there are horizontal lines, then it hits a vertical line before going into red. I did have the mixer level wise calibrated.

maybe I need a compressor with this mixer.
 
If your mixer doesn't have a tone generator, then you might want to consider buying a GTC Tone Plug to help calibrate your mixer with your camera. The Tone Plug can generate a 1 Khz 0 dB signal that you can calibrate your camera's sound level at -12 dB with. The reason for -12 dB on the camera, is to allow for some headroom for momentary very loud sounds. If you record 30 sec of tone at the start of each new set-up, you can then use this sound to calibrate the sound level for all your clips when you are editing.

GTC Tone Plug
http://www.tangible-technology.com/gtc/TonePlug.html

GTC Tone Plug at B&H PhotoVideo
http://www.bhphotovideo.com/c/product/197233-REG/GTC_Industries_TP1_TONE_PLUG_11_Function_Audio.html

:D
 
Really appreciate the response. Could you speak more on recording 30 seconds of tone. I'm probably wrong, but when I hear tone, I'm thinking that steady sound you hear when looking at the color bars. And I don't understand fully about "before the set up" Am I adjusting per ambient sound, dialog spoken, from the computer tone, etc.?

As you can see, I'm a little lost at this point. I'm very interested to hear what you have to say. Thank you
 
Big ScareCrow said:
when I hear tone, I'm thinking that steady sound you hear when looking at the color bars.
Click to expand...

Yes, that's the standard 1 KHz tone.

Big ScareCrow said:
And I don't understand fully about "before the set up" Am I adjusting per ambient sound, dialog spoken, from the computer tone, etc.?
Click to expand...

Sorry, I should have explained myself better. What I meant was, each time you take everything apart to move your gear to a different location, you should go through the same "tone" set-up again. If you do everything perfectly then all your tone samples will be the same, but if you accidently set the sound level higher or lower on a new set-up, you'll notice this when editing by checking the tone sample, and can easily adjust the sound level in your editor to match all the other set-ups.

Also, if you are working with more than one camera, you can catch differences in sound levels between cameras by checking the tone sample.
 
Big ScareCrow said:
and this tone plug actual creates the tone for both the mixer and camera?
Click to expand...

Tone Plug is plugged into the mixer, mixer feeds the camera. ( mixer also generates the 48v phantom power that the Tone Plug needs to operate )

Step 1: Plug the Tone Plug in to a mixer channel.
Step 2: Adjust Tone Plug to generate 1 KHz signal.
Step 3: Adjust the mixer gain for Tone Plug channel so that the mixer shows 0 dB level.
Step 4: Feed line-out signal from mixer to camera.
Step 5: Adjust camera level so that the Tone Plug signal shows a -12 dB level.

Camera is now calibrated for the mixer.
 
Brother you are the bomb. Thanks for walking me through these steps. I want you to know, that I'm going to execute those instructions. You've just helped me up my game another step. Thanks again for your patience.

Crow
 
on dvx the -12 is the last white bar, the one with the line through it. if im understanding the question.

personally, i prefer to line up at -20, but thats jut me. and my employers...
 
Can mega-decibel audio recording damage HVX-200?

Can mega-decibel audio recording damage HVX-200?

No luck searching this question, so here goes: I'm occasionally asked to record air shows & civil war reenactments. The sound level is deafening; jet engines, live fire .50 cal Brownings, civil war cannons, etc. Sound so loud, it parts your hair. I don't want to damage any internal audio components. Any suggestions? I can foley in the sound later in needed, just don't want to harm the camera..... thanks
 
hi, i'll have a go at your question gary since i asked the same question before.

when recording extremely loud sounds that still distort even if you turn the level way down thats because the distortion is there before it enters your mixer, therefore you have to use pads to pad down the sound a few decibels
 
Yes, you must pad the mic line 10 or 20 dB before it enters any (other) electronics. With really loud sounds not even that works, because it is possible to have mechanical distortion in the microphone. The microphone diaphragm can move only so much without distortion, sounds too loud might even break the mic.

Mic manufacturers, decent ones, state the loudest volume the mic can handle cleanly.
 
Also a minor warning with gun shots etc. The transient on those things can blow the mic diaphragm if your too close. That kind of damage is essentially unfixable. You need to replace the capsule and depending on the mic that might not be possible at a cost that make sense. So be CAREFUL. Big jets aren't very likely to do permanent damage (except to your ears, you should be wearing protection if your close to any of the above). The HUGE low end though will tend to cause hard-disk errors and crashes. Flash cards don't seem to have a problem and tape???
 
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