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Old September 21st, 2009, 07:51 PM   #1
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Mixer levels

I'm new to using a mixer (Pro Mix) and I find levels are a little low. When I do a tone test of 0db, my camera (Sony Z1u) shows only 1/2 bars for levels. Is this normal?

When I have a mic plug directly into the camera I'm use to setting the gain so the peaks are close to touching the red but when I'm using the mixer, the mixer's indicator is touching the red on its level display but its lower on the camera. I've read through the manual and check my camera and mixer settings and they are correct:
Camera: manual gain set to 5, line input, limiter off,
Mixer: line output at 0db (the highest setting)

Should I just increase the camera's gain? I was using 7 but didn't want to max it out to 10 because it could introduce noise. But even when the camera's gain is set to 10 it still a few bars below red.
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Old September 21st, 2009, 08:52 PM   #2
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Pete,
You have to align the output of the mixer to the recorder (in this case your camera). Not sure what the bars level is on your camera but you want to set your tone at -20 or -12 depending on how brave you are. Yes you should increase the gain at the camera if the levels are low. Peaks can and should go above where you set your tone. I personally like to set my tone at -20 and peak around -12
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Old September 21st, 2009, 10:13 PM   #3
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Ok, I'll increase the camera gain. The levels indicator on the camera don't have db associated with them and are only a visual indicator.
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Old September 22nd, 2009, 07:49 AM   #4
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Pete, the Z1U does show db levels. Press the "Status Check" button on the back of the camera.

As Daniel suggested while feeding a 1 khz tone set the output on your mixer to 0db (line out), set the input level on your camera to -20 db (line level in, phantom off) with peaks not to exceed -12 db. These are considered broadcast standards.
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Old September 22nd, 2009, 08:37 PM   #5
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Originally Posted by Rick L. Allen View Post
Pete, the Z1U does show db levels. Press the "Status Check" button on the back of the camera.

As Daniel suggested while feeding a 1 khz tone set the output on your mixer to 0db (line out), set the input level on your camera to -20 db (line level in, phantom off) with peaks not to exceed -12 db. These are considered broadcast standards.
I forgot about the Status Check.
I have line level in set, I might have phantom on, I'll turn that off, -12db peaks.
thx all
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Old September 23rd, 2009, 12:05 PM   #6
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Pete,

To be clear. The audio meters on your mixer should read 0 db for most mixers and -20 db (when the scale is -100 to 0) when feeding a 1 khz reference tone to any equipment.
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Old September 23rd, 2009, 02:20 PM   #7
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If you're referring to the mixer I'm thinking of, it did have low output designed to match up with the popular DVX-100 camera.
You can also set the mixer output to mic level and use the mic input setting on your camera. That might be a better match. I've done that before when a device needed more signal than that mixer could give on line output.
Be aware it's pretty easy to get clipping within that mixer itself if you try to push it too hard. Probably better as you've already said to raise the camera gain a little as long as it doesn't create too much extra noise.
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Old September 25th, 2009, 08:52 PM   #8
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Quote:
Originally Posted by Jay Massengill View Post
If you're referring to the mixer I'm thinking of, it did have low output designed to match up with the popular DVX-100 camera.
That matches exactly whats going on. The mixer is from the company I work for and they said levels are fine for their cameras which are Panasonic DVX. I find it odd an expensive mixer would match levels with lower end camera.
Quote:
You can also set the mixer output to mic level and use the mic input setting on your camera. That might be a better match. I've done that before when a device needed more signal than that mixer could give on line output.
Be aware it's pretty easy to get clipping within that mixer itself if you try to push it too hard. Probably better as you've already said to raise the camera gain a little as long as it doesn't create too much extra noise.
I raised the camera gain and that was sufficient, but the mic input is a good option to keep in mind.

Last edited by Pete Cofrancesco; September 26th, 2009 at 06:53 PM.
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Old December 7th, 2009, 07:07 PM   #9
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Mix output attenuation confusion

Hi folks

Perhaps someone can clear up this techncial issue so Im not jsut going thorugh the mptions but understand it.

Say for example

mixer tone at 0vu/0dbu is lined up to the recorder at -20, with peaks at 8dbu = -12dbfs

So standard levels

When the output is at line level or attenuated to mic level, does this actually in essence cut the signal

for example say the output is line level 0db..... if the mixer meter says like 8dbu, whay happens at the outputs if its set to line level 0 - 16db or mic level 40 - 56db.

Im rather confused as you line up the mixer at 0dbu for the nominal level but you peak at 8dbu, yet standard line level is 0 or 4dbu, so do all the signals get cut to these?
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Old December 8th, 2009, 03:57 PM   #10
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Lee,
The recording levels on your mixer meters and the camera shows you the deflection of the signal you are sending and recording while the switches which control Line Level and Mic Level are dealing with the size of the signal. Yes Line Level signals are a much bigger signal than Mic levels signals in size. And there a various ways to cut and amplify signals some of which can a cause of loss of audible quality and some which apparently don't. There is a relation between what is on the meters and the size of the signal but each of these is defined by the manufacturer of the gear and depends on what they specify which may or may not be standard so we use test signals to try and align what a mixer says is its output and what a recording device is expecting. The signals are not cut or limited unless you or the manufacturer set a limiter up on the output device to do so at specific level which then would be at the same point in the signal deflection regardless of whether the output was set to line level or mic level. Recorders can also have limiters and gain adjustments on inputs as well but usually cannot compensate for a line Level coming in when the input is set to Mic or boos a mic signal up to Line.
The question of quality of signal as to which is better Line or Mic is an interesting one as some machines use mic level inside the recorder so they convert the incoming signal to mic while others use a Line level signal inside the machine and convert incoming mic signals to line for recording. I leave it to other people to make those distinctions although I favor Line Level outputs from mixers in the field because they are less susceptible to interference but some machines don't handle them as well as mic levels. Knowing your recording systems abilities and good monitoring are important to deciding what your switches should be set to. HTH
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Old December 8th, 2009, 09:26 PM   #11
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more sound

so the output level doesnt attenuate the mixed signal level, just the strength of it sort of?

It just gets a little hazy because when it says mic level -40db, it makes it seem like its cutting that off your signal level reducing say a signal of 16dbu on the mixer meter down to -24dbu at the outputs.... bare in mind Im on a quest of technical knowedge so this may seem stupid but gotta get my lil head round it :D
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Old December 8th, 2009, 10:38 PM   #12
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Lee, not sure what mike level you're seeing, but the signal level out of mikes runs in the -40db range --- less for dynamic mikes, usually, and usually this or more for condenser mikes. You amplify that -40 db (or whatever) in your mixer to provide a signal that is of the appropriate level for your recording device. And that's the part that's hard to figure, with dBFS and dBv and all the other variations of signal measurement, it gets pretty confusing. But I think what you're talking about is the signal level that the mike puts out before it hits the preamps. /Battle Vaughan

PS If you are outputting to a recording device whose input is mike level, then (at least with my field mixer) you set your mixer levels to 0 db on the test tone, voices come in on a vu meters at about -7, and by selecting mike level output on the mixer, the signal is attenuated appropriately by the mixer to match the recorder. So you use the same drill if outputting to a line level device, but set the output to line level, and again the mixer takes care of it. /BV

Last edited by Battle Vaughan; December 8th, 2009 at 10:44 PM. Reason: addendum
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Old December 9th, 2009, 07:04 AM   #13
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levels again

thanks B but I think I jsut wasnt beong cleaer enough.... Steve House grasped it in the end though.

"With no attenuation, 0dB on the meter means you're putting on a 0dBu signal from the main outputs. Thus a +16dB meter reading means you're putting out a 16dBu signal from the main outs. But if you use the setup menu to attenuate to the output to minus 40, 0dB on the meter reading means you're putting out -40dBu from the main outs. Your analogy to reducing a master fader is a good one"

It may seem like such an obivous thing now, but I have no technical background so I wanna learn what it all really means, its suprising how many 'pros' ive spoken to who just go through the motions of lining up and gain matching, without really knowing why!

If it goes out a mic level on the mixer thereby attenuating the original signal level and then it is boosted on the recorders trims to pull it up to the equivalent DBFS theres gonna be a poorer S:N?
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Old December 9th, 2009, 07:38 AM   #14
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I've tried to read this thread and I'm not sure all the information is good. There are a lot of assumptions flying around and they may or may not be valid. I'll bypass all that and mention something totally different that Lee may find useful.

You have the analog world and the digital world.

In the analog world, things are grey. In the digital world, things are black and white.

In digital, zero means thou shalt not go above me. Audible nastiness will occur.

In analog, eh, go ahead and do what you want. Audible nastiness will occur at some point over zero--highly dependent on the equipment.

Your mixer is likely totally analog. Your recorder is likely digital at its core.
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Old December 9th, 2009, 07:49 AM   #15
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Broadcast standards has nothing to do with the levels you are recording on to your camera or recorder. I try to record as hot a signal as possible. Peaking at -12dB is really too low for any digital camera or recorder. I would suggest peaking closer to -6 on average but peaking anywhere below 0 is fine but it makes sense to have at least a few dB of headroom. I use a Sound Device mixer that has a decent limiter so I set levels so that my mixer's meter is tapping the limiter occasionally while maintaining around -6dB peaks.

Andy
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