Plugins on Master Fader or Main Mixdown Track

[AlexLakis]

Okay, I'm not sure all the pieces are here yet, but here's what's possibly causing your problem:

By default in Pro Tools, inserts on regular tracks are PRE-fader. That means the audio is processed by the plugin REGARDLESS of what the fader volume for that track is set at. Therefore, moving the volume fader on the track does not effect the plugin's processing. It DOES, however, effect how it "hits" the master fader.

Inserts on master faders are POST-fader. That means the audio is processed by the plugin AFTER the volume has been modified by the fader. Therefore, any changes to the volume you make on that master fader will effect how the plugins on said master fader are "fed."

Could this be the cause of the differences you're experiencing?

As far as your previous statement, there is no additional "strain" on master fader plugins as the signal is summed before it hits the plugins; Therefore, the plugin will always be processing a single mono or stereo signal (depending on if your master fader is mono or stereo.) Of course, that signal will be the SUM of all of the tracks being fed to it, meaning that you will need to compensate when setting levels like in the analog realm; I'm just saying that there is no additional CPU strain (if that's what you meant.)

[studioslave77]

It would seem true if the volumes were different, but both are equal

[studioslave77]

yea sorry, both are at 0

[Camilo Toledo]

Take also in consideration that you are using an analog mixer, and that is going to affect the sound of your mix. Once it comes back to PT from that mixer it would have changed.

[studioslave77]

I know...BUT im comparing 2 tracks that are exactly the same, shouldnt matter how i recorded them, ...Im not comparing 2 different tracks.

[nikki-k-again]

Hi!
OK, I am trying to understand this post, but due to what appears to be a basic (and extremely common) misunderstanding of how PT works, it is difficult to be 100% sure of the situation...

First, "mastering" a mix while mixing is an incredibly bad idea. I will not even touch on why, as it would require more than a thread.

Now, if one were looking to have a mix processed lightly before mastering, which is not out of the question, and if your question is, "Why am I hearing a difference between a stereo mix being bussed to a stereo Audio Track with the summed mix effects being placed on the actual stereo Audio Track versus placing them on the Master Fader of the Buss used to sum the mix?" then there is only one answer: you are not operating at unity at the summing point.

Understanding PT terminology and "flow charting" of how PT works is essential. Master Faders are one of the single most misunderstood "pieces" of the PT world. Master Faders are inline objects on every internal buss, as well as every output buss. Input busses are not modifiable or observable in PT. The Master Fader object itself is ALWAYS present. You can choose to create a Master Fader track, and then choose to use that to provide metering, level control, and/or effecting of a like width Master Fader object that is on any internal or output buss you have setup in PT, via the I/O settings window (Setup->I/O). Typically, with LE, the user will setup at least a single stereo output buss, which is assigned to depart via 2 outputs of their Digi hardware to their audio monitors. In your case, you are sending out via 2 output busses and thus physical outputs on your Digi hardware to your analog desk- correct?

OK, if you are doing that, then the next question is: are you bussing the entire summed mix to a stereo Audio Track, and then setting the output of that stereo Audio Track to the stereo Output Buss going to your hardware outputs that are cabled to your analog desk? If yes, then is it the Master Fader object on that Output Buss that you are creating a Master Fader track to control/meter? If yes, then is your question: If I place the same, single effect plugin on the Audio Track receiving the summed mix on the output buss' Master Fader, and if both Master Fader and Audio track are set to 0dB, why am I hearing a difference?

As mentioned, Master Fader objects only allow post fader effect inserts. As such, they are *victim* to the user's fader settings. If a Master Fader track's fader is left at 0dB, and no effects are inserted, it DOES NOTHING. If the Audio Track's fader is at 0dB as well, then the signal entering the Audio Track is the same as the signal exiting, and also the same post- 0dB, unaltered, Master Fader object. Thus, inserting an effect on the Audio Track OR on the Master Fader track assigned to that Master Fader object in the described case will result in identical signal at the Output Buss' exit point.

At the basic routing level, it is *simple* math. The slightest change to the described scenario WILL result in a different result.

BTW- if the question is what I described, it has been asked and shown to be so via theory, and in actual practice (via phase canceled results). Additionally, the other similar "myth" of a mix to stereo Audio Track vs File->Bounce to wav yielding different results was also disproved ...seems to appear with (at least) every major PT revision, especially from 5 to 6, and then 6 to 7. If a non-phase canceling result has occurred, it would be interesting to see/hear.

[Camilo Toledo]

Additionally, the other similar "myth" of a mix to stereo Audio Track vs File->Bounce to wav yielding different results was also disproved

Yes, but only if both bounces, the mix to the stereo track and the regular bounce to wav are done ITB.

In his case, he is sending an stereo signal from the 002/3 to an unknown mixer, and then routing that signal from that mixer to PT. Can you tell us why you think the signal ( which has obvioulsy gone thru the circuitry of the mixer) is the same and does not yield different results?

[nikki-k-again]

Sorry I was not clear enough... all the stuff I explained was for mixes bounced/mixed ITB. Hardware as inserts would still count as "MITB" in these cases; however, one could wonder if natural variances in analog components *could* introduce even a slight bit of randomness into things, and thus cause any two bounces to not be 100% identical...but I doubt it would be significant enough to allow one to identify each bounce produced.

The mix to an Audio Track was not specifically stated as being recorded to that Audio Track, but rather implied, since the other option was a File->Bounce recording. Obviously anyone comparing either of those two with a mix passed thru a hardware desk (analog or digital) and back to an Audio Track in the same session would find a difference in sound; the desk would act as a coloring effect in that case. However, if the desk is used as an insert (send->return) in both scenarios, placing it as an insert on the Master Fader of the Output Buss being used to send to the desk OR placing it on the Audio track being used to record the mix, OR simply using the inputs for the desk via Output Busses and then returning it into the mix would result in the same audio file if all the "rules" were followed. The signal chain would HAVE to be set properly to produce identical summed mixes. Even so, as stated above, analog components *can* introduce variations that could result in non-nulling bounces. I am sure there are plug-ins that might emulate this. (if not, might be a cool idea-lol...)