Gain Staging??

[zedhed]

Check this out...it may be of some help.

http://duc.avid.com/showthread.php?t=343241

[DC-Choppah]

Originally Posted by Raoul23

When I track I have the metering set to pre fader. I always try my hardest to have the level just touching the yellow on the loudest parts (-6) and have the input monitoring selected (as I'm on HD) so I can monitor the signal coming in. When I add a plugin say for example waves CLA 2A the input level increases on the fader meter. I then check the input on the plugin is just hitting -6 which is the same as the signal coming in when the plug is inactive. If this is correct and the fader meter shows an increase in signal I turn down the output on the CLA 2A making the fader level meter the same for both when the plugin is active and inactive.

Now if I add another plugin I want the input to be -6 on the plugin meter and weather the plugin is active or inactive the fader meter should still be hitting -6 as well, have I got this right???

Please keep in mind that the plugin does not affect the level of the recorded signal. The plugin is in the digital domain which is after the signal has been converted. Once in the digital domain the headroom is massive in PT since it is using internal math. You can even have a channel showing 'clipping' on the meter, but if this is only after a plugin has been inserted, this 'clipping' isn't real.

Clipping on the master fader is always real because it has to go through the converter again on the way out of the digital domain.

[Raoul23]

Originally Posted by DC-Choppah

Please keep in mind that the plugin does not affect the level of the recorded signal. The plugin is in the digital domain which is after the signal has been converted. Once in the digital domain the headroom is massive in PT since it is using internal math. You can even have a channel showing 'clipping' on the meter, but if this is only after a plugin has been inserted, this 'clipping' isn't real.

Clipping on the master fader is always real because it has to go through the converter again on the way out of the digital domain.

Very handy to know. But if the clipping is not 'real' as you say why do they have the indicator light up ????? Very strange


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[JFreak]

Originally Posted by Raoul23

Very handy to know. But if the clipping is not 'real' as you say why do they have the indicator light up ????? Very strange

Real clipping as in recorded signal clipped before it was written to a WAV file. Yes you can also clip your mix anywhere, but that can be fixed by mixing properly. If your recording (audio file) is clipped, then the clipping is real.

[Raoul23]

Originally Posted by JFreak

Real clipping as in recorded signal clipped before it was written to a WAV file. Yes you can also clip your mix anywhere, but that can be fixed by mixing properly. If your recording (audio file) is clipped, then the clipping is real.

So the plugin clipping light does mean clipping then????? Now I'm really confused lol


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[CME]

Yes clipping the input/output of a plug-in is real, but not permanent. You can simply lower the level going into/out of the plug in and the problem is fixed.

However if you have the gain on the preamp/interface too high you will clip the converter. Once that happens there is no way to truly fix that. There are some ways to make it better, but it can never be truly "unclipped".

[DC-Choppah]

You can have the PT meter show clipping after you install a plugin and have no distortion actually present. The math used in the digital domain has massive dynamic range. The PT meters are relative to the external (audio interface) dynamic range. As long as you recover the right signal level at the end of the digital chain you are OK.

A fundamental experiment is to put in a gain plugin (or multiple gain plugins) and see how much gain you have to add until a sin wave distorts. Insert an oscilloscope on the master track and look at the sin wave until you see it clipping. Sort of a fundamental intro to digital audio - what it really means.

[Raoul23]

Don't mean to hi jack the thread but I'm a bit confused about the point of pre fader metering once the recording has taken place. I record a track and it hits around -6db on the pro tools meter I then add AC1 by McDSP for example and pick console 2 as the setting. Now according to Charles dye you push the input so the yellow light is bouncing evenly now if I do this it sends my pre fader level in to the red but if I switch to post fader level its not that hot at all. I then change back to pre fader and reduce the output on AC1 to reduce the pre fader level. Now if I'm clipping pre fader with a plugin on the insert but its not clipping when the plugin is off the track. Do I still get distortion ???

[CME]

Kind of lost at exactly your question but in general any levels that clip anywhere are normally bad.

I like to keep my pre fader levels well away from clipping. Most plugs have input and output controls. So if a certain plug needs more level into it, I'd use the plugs controls to do that. That keeps the level into it from being too hot.

[bileshake]

I'm glad to see this conversation. I've been messing with this for awhile and I tend to run everything too hot from the start. Fighting the red ceiling every time I add a plugin.
I'm gonna actually try to keep everything down and hopefully gain a little more headroom in my mix. In my opinion, headroom can always be taken out but you can't add it later. I'll keep the board posted and maybe show some progress.

\m/