Using all 4 channels of audio...?

F

filmguy123

Veteran
So I have a couple of questions about utilizing all 4 channels of audio that the HVX offers... I numbered the questions to make responding easier.

1.) To clarify, DVCPRO and all DVCPRO-HD modes (720p+) record 4 channels of audio no matter what, is this correct?

2.) When in a mode that records 4 channels of audio and no XLR connection is present, does the in-camera microphone get recorded INT(L) to 1, INT(R) to 2, and then again INT(L) to 3, INT(R) to 4?

3.) When I do have an XLR connection attatched, to get stereo sound, MUST I be plugged into XLR input two? Or can I just tell channel 1 to come from the XLR input 1? How would this setup look when pulling it into FCP?

4.) When I have an XLR mic on channel 1, and an XLR mic set to channel 2, will the first two channels be the XLR 1 input and the next 2 channels be the on camera input? Or does the on camera mic ALWAYS record?

5.) If I am shooting normal dv25 footage onto a P2 card, can I utilize 4 channel audio?

6.) When shooting on a normal shotgun mono mic (to clarify, shotgun mics are mono... right?) is it even neccesary to have the input recorded to two channels, or will it sound the same if I just record it to a single channel? And/or, can I just take single channel that has been recorded and copy/paste it in FCP to make it play back through 2 channels and have the exact same sound?


Thanks a lot for helping me understand this...!
 
filmguy123 said:
1.) To clarify, DVCPRO and all DVCPRO-HD modes (720p+) record 4 channels of audio no matter what, is this correct?
Click to expand...

No, its not.
DVCPro has 2 channels of audio.
DVCPro50 and DVCProHD have 4 channels of audio.

2.) When in a mode that records 4 channels of audio and no XLR connection is present, does the in-camera microphone get recorded INT(L) to 1, INT(R) to 2, and then again INT(L) to 3, INT(R) to 4?
Click to expand...

Not necessarily.
The in camera microphone ALWAYS gets recorded to two of the tracks.
And if you have your camera set to record the in camera mic as opposed to the XLR inputs, then yes - you will have 4 tracks of incamera mic audio.

3.) When I do have an XLR connection attatched, to get stereo sound, MUST I be plugged into XLR input two? Or can I just tell channel 1 to come from the XLR input 1? How would this setup look when pulling it into FCP?
Click to expand...

Not sure what you're asking here.
You can send INPUT 2 to both track 1 and track 2.
INPUT 1 can only be sent to one track.

4.) When I have an XLR mic on channel 1, and an XLR mic set to channel 2, will the first two channels be the XLR 1 input and the next 2 channels be the on camera input? Or does the on camera mic ALWAYS record?
Click to expand...

ON camera mic ALWAYS gets recorded.

5.) If I am shooting normal dv25 footage onto a P2 card, can I utilize 4 channel audio?
Click to expand...

No.

6.) When shooting on a normal shotgun mono mic (to clarify, shotgun mics are mono... right?)
Click to expand...

Yes.

is it even neccesary to have the input recorded to two channels, or will it sound the same if I just record it to a single channel?
Click to expand...

Its not necessary at all to record it to two channels.
If I'm not using the other input, I generally send the signal to both channels and turn one a bit lower than the first, that way if the sound pops higher than expected, I can go to the other track and hopefully save it in post.

And/or, can I just take single channel that has been recorded and copy/paste it in FCP to make it play back through 2 channels and have the exact same sound?
Click to expand...

Absolutely.
In fact, you don't have to copy and paste it - just make sure your pan is set to center ("0") for that sound clip.
 
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Oh wow, thanks for the great and quick reply. To clarifications now:

1b.) So recording any mono signal, which if I am correct most XLR inputs like shotguns, cardiods, etc. are always mono - it is USELESS to record it to two tracks, unless I am want have a lower track to stop it from popping?? All this time I thought I had to have my XLR inputs set to record to both tracks...

2b.) So do you usually use XLR input 1? All this time I have been using input 2 from a shotgun or some other source and recording to both channel 1 and channel 2.

3b.) So I can get one wireless lavier on say, channel 1; one shotgun on channel 2, and then channel 3/4 are dedicated to the on-camera mic?

4b.) So the on-camera mic is STEREO... so I know both channels always get recorded, but theoretically, if you only recorded one - say INT(L) the sound would sound half incomplete? Why is this different, and how common are stereo mics in video production?
 
filmguy123 said:
1b.) So recording any mono signal, which if I am correct most XLR inputs like shotguns, cardiods, etc. are always mono - it is USELESS to record it to two tracks, unless I am want have a lower track to stop it from popping?? All this time I thought I had to have my XLR inputs set to record to both tracks...
Click to expand...


"USELESS" is a pretty strong word.
But yes, it is redundant.
You are not gaining any quality in your audio by sending that same mono XLR signal to both channels.

2b.) So do you usually use XLR input 1? All this time I have been using input 2 from a shotgun or some other source and recording to both channel 1 and channel 2.
Click to expand...

If I only have 1 source of audio I generally send it to channel 2 and record it to both channels - there is really no reason not to if you are only using 1 souce of audio anyhow.

3b.) So I can get one wireless lavier on say, channel 1; one shotgun on channel 2, and then channel 3/4 are dedicated to the on-camera mic?
Click to expand...

Absolutely.

4b.) So the on-camera mic is STEREO... so I know both channels always get recorded, but theoretically, if you only recorded one - say INT(L) the sound would sound half incomplete? Why is this different, and how common are stereo mics in video production?
Click to expand...

I'm not sure what you mean by 'half incomplete'
A stereo signal is basically nothing more than 2 mono signals recording simultaneously.
Of course in the case of the on camera mic (which you probably shouldn't be using for much more than a guide track anyhow) those two mono tracks are favoring the left and right side of the camera.
 
Luis Caffesse said:
No, its not.
DVCPro has 2 channels of audio.
DVCPro50 and DVCProHD have 4 channels of audio.
Click to expand...
Correct, but not. You can also get 4 channels of audio in DVCPRO by choosing it in the recording setup menu; there's a choice there for 2 or 4 channels in 25mbit mode.



The in camera microphone ALWAYS gets recorded to two of the tracks.
And if you have your camera set to record the in camera mic as opposed to the XLR inputs, then yes - you will have 4 tracks of incamera mic audio.
Click to expand...
Bzzt. Wrong answer. :)

Two channels will come from the XLRs, two from the in-camera mic. You can't get 4 channels of in-camera mic. You select which source goes to channels 1 and 2; the other source gets automatically routed to 3 & 4. So you can have XLR 1 on 1, and XLR 2 on 2, and in that case in-camera mic L goes to 3 and in-camera mic R goes to 4. Or you can choose in-camera mic L to 1, which sends XLR1 to channel 3. And you can choose in-camera mic R to 2, which sends XLR 2 to channel 4.
 
Barry_Green said:
Correct, but not. You can also get 4 channels of audio in DVCPRO by choosing it in the recording setup menu; there's a choice there for 2 or 4 channels in 25mbit mode.
Click to expand...

Wow, I had no idea.

You can't get 4 channels of in-camera mic. You select which source goes to channels 1 and 2; the other source gets automatically routed to 3 & 4. So you can have XLR 1 on 1, and XLR 2 on 2, and in that case in-camera mic L goes to 3 and in-camera mic R goes to 4. Or you can choose in-camera mic L to 1, which sends XLR1 to channel 3. And you can choose in-camera mic R to 2, which sends XLR 2 to channel 4.
Click to expand...

Well, you know what they say about assumming.....
I don't think I ever shoot without something going into the XLR inputs, so I was just extrapolating from that. Maybe from now on I should just send people your way when they ask something like this.
:)


Thanks for clearing those details up.
I'd hate to be the guy spreading misinfo (which apparently I am)
:thumbsup:
 
Hey Luis don't worry about it, you were super helpful!

And Barry, you really know you're stuff inside and out, consistently. I'm always impressed. Thanks for clearing up those few areas.

Thanks to both of you guys!
 
1,2 or 4 audio channels/tracks, audio recording requires:
- LEVEL adjustement in the optimal signal/noise ratio range (-12 -> 0)
- DYNAMIC control avoiding RMS clipping (Peak ok)

So, beyond basic sound taking, where you can expect to handle level/dynamic easily, incorporating a limiter in the audio chain, by using a small field mixer, is almost mandatory, even if you choose "the best mic".

By example, atiaudio.com features the MX100C, with 3 mikes and 1 output, with limiter, all XLRs & Bal/Unbal Output.

If you get an audio feed from a mixing console, check with the audio engineer a prefader mix and settle the constant output level. It is wise to monitor it, too.
 
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Back to the original topic...
1) So if I am recording a lav on channel 1 and 2 (connected to xlr input 2 on the HVX)
shooting DVC-ProHD. Is there anyway to NOT record the oncamera mic to channel 3 and 4?
2) When shooting DVC-ProHD with above setup am I monitoring (through the headphone jack on the HVX) all 4 channels or just 1 and 2 ?
 
Jon Fulton said:
Is there anyway to NOT record the oncamera mic to channel 3 and 4?
Click to expand...
hammer-1.jpg



No sense in not recording them anyway. It's not like you'd save data bandwidth, they're just blank tracks if you don't use them.
 
Barry_Green said:
2. You can select whether you want to monitor 1/2 or 3/4 in the menus.
Click to expand...
Thanks Barry,

although I have looked again in the Setup Menu List of the manual I could not find a setting to select channel 1/2 or 3/4 to be monitored through the headphones. The closest I could see was HP MODE which selects either Live sound or Recorded Sound.

Can you let me know what setting selects Channel 1/2 only to be monitored?

Thanks.
 
Barry_Green said:
1. No way to turn the internal mic off.

2. You can select whether you want to monitor 1/2 or 3/4 in the menus.
Click to expand...

I just make sure I deselect the tracks I don't need when importing to FCP. That's saves me space correct? Eventhough there might be "nothing" on tracks 3 and 4 they still conain data right? Wish there was a way to globally modify import settings. Deselecting tracks or selecting between mono or stereo upon P2 import sucks when you have to do it individually for every clip when you have 40+ clips to import.
 
I don't have my HVX here right now so I can't look up the exact menu... I know you can do it in playback mode, maybe you can't in live recording...
 
luis, you mention using channel 2 if only using one xlr input, why is this?
i shoot interviews using input 1 for radio lav mic and input 2 for shotgun,
in circumstances where the shotgun is'nt used am i better off switching the lav to input 2?
 
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