When is a plug in not plugged in? And are DAW's much more tempermental than we think?

Discussion in 'Tracking / Mixing / Editing' started by jmm22, Jan 6, 2011.

  1. jmm22

    jmm22 Guest

    When is a plug in not plugged in? And are DAW's more temperamental than we think?

    Two recent experiences were eye (or ear) opening to say the least. The first occured when I decided to re-order how the tracks appear in the DAW, merely to make things look more organized. I had already exported a wav file with the disorganized appearance, ordered the track in more logical groupings, and re-exported a wav file. Now I would swear they sounded different, very subtle, but different.

    I am willing to leave some small window of doubt about my observations of the above, but on the second part I am about to describe, I am positive.

    I had had a certain mix, and liked it. A few days later, during some experimentation, I made several changes to it, and inadvertently saved it instead of saving as something else, meaning that I changed a mix I did not want to change.

    I spent the next few days reverting the settings using notes, other versions of minor difference, and memory. Yet even after restoring everything I could identify, the mix was different, not bad, but still slightly different.

    But just now, I remembered one change I forgot to restore. In the first export, I had two plug-ins installed, a simple limiter and a mild high frequency boost plug in across the two bus, but I exported the file with the bypass switches on, meaning the effects should not be printed to the export file.

    On the version I was hoping to restore exactly, I did not have these unused plug ins installed. I thought it could not make any difference, but after laboring endlessly to get it exact, I began to wonder if they could indeed have an effect, even if they are bypassed and thus not functioning.

    I just installed the two plug ins, and bypassed them, and viola, I had the mix restored identically. It seems having plug-ins installed even if they are bypassed (and thus not functioning) will have a sonic effect. Of this situation, I am certain.

    Is this a known phenomenon? Any other thoughts? It is slightly distressing to think that a non-functioning plug in could have an effect, as it adds a whole new order to the already infinite combination of possible settings.
     
  2. JohnTodd

    JohnTodd Well-Known Member

    Sounds weird to me. I would assume that a digital bypass is a true bypass.

    Try a test:

    1. Import both mixes into a new empty project on two tracks. Make sure they are EXACTLY aligned.

    2. Throw one track 180 degrees out of phase.

    3. Put the faders at unity. Make sure all settings are identical for both tracks.

    4. Set pan at "middle" or "straight up" for both.

    5. Play it back.

    If they are the same they should cancel each other out, and you'll hear nothing. If you hear something, that's the difference between the two tracks. This experiment will scientifically test your observation, thus ruling out variable we can't account for.
     
  3. natural

    natural Active Member

    Yeah, even though they're bypassed, they still provide latency to the track just for being there. Some DAW's have a way of making unused plugs muted, so as to not cause latency problems. (also frees up ram etc) Depending on what kind of tracks they're on, it may or may not make a noticeable difference.
    JohnTodd's method should clear up any doubt.
     
  4. jmm22

    jmm22 Guest

    I don't think the test can be reliably applied to the wav files I have at present. Here is why. I said the newly restored mix is identical (after making incremental changes) but I should have said it is now audibly indistinguishable. Even if the test indicates a difference, I could not attribute the difference to the bypassed plug ins with absolute certainty. However, I can repeat the whole experiment by exporting two new mixdowns, one with the plugs bypassed, and the other with the plugs deleted. I will try this today and report back. Mind you, regardless of the outcome, I cannot see how the results could nullify my observation that a mix that was clearly not indistinguishable was rendered so merely by adding two missing bypassed plugs, particuarly if this observation re-occurs with brand new mixdowns. But I will leave all doubt and questions aside until I conduct the experiment.

    The test reminds me of Bob Carver and his challenge to sonically replicate another companies amplifier, which he did using nothing more than differences. It is an interesting read.

    The Carver Challenge | Stereophile.com
     
  5. jmm22

    jmm22 Guest

    I just finished the experiment. I exported the two mixes, one with stereo bus plugs bypassed, and the other with the plugs deleted. I then imported the two to a mastering window, and phase reversed one track. This resulted in a very audible drum track, to the exclusion of everything else. The fact that all other instruments vanished indicates the tracks were synchronized and that the phase reversal worked. I then reverted the phase on that track, and changed the phase on the other track, with identical results.

    The residue drum track was mostly high frequency content, yet with some bass. If I were to liken it to an equalizer, it would be something like an extreme smiley face.
     
  6. TheJackAttack

    TheJackAttack Distinguished Member

    I'm on the Droid so hard to answer thoroughly. In my DAWs there are many spots in which to put fx. Some of them send pre fade to other locations. If I turn the fx on the stick itself off but haven't stopped the send portion audio will still be present, just not linearly through the original channel.
     
  7. JohnTodd

    JohnTodd Well-Known Member

    Yes, but he's using completed exported mixes. Should cancel that out, too?
     
  8. TheJackAttack

    TheJackAttack Distinguished Member

    If the plug is present and sending audio info it will be included in the final mix.
     
  9. TheJackAttack

    TheJackAttack Distinguished Member

    Furthermore, since the inverted track didn't sum to zero I know the audio is being sent to a bus or track somwhere else, like a verb.
     
  10. jmm22

    jmm22 Guest

    I am not sure I follow what you are saying John. Can you clarify? The bottom line is I have two seemingly identical mixes, except for two plug ins being either bypassed or removed altogether at mixdown. They sound different after the export mixdowns, and different in a way that corroborates with the residue from the phase inversion experiment, that being one track (the one with the plug bypassed) is slightly brighter or more present than the other. To me, the primary reason for the difference must be the two plugs. If you do not think it is the two plugs in question, what cause are you attributing the difference I am hearing, and observing in the phase inverting experiment?

    I thought we were under the impression that bypassed plugs do not send information to the mixdown. I was, until this experience.
     
  11. JohnTodd

    JohnTodd Well-Known Member

    We are in agreement...there is a difference when there should not be. I thought bypassed plugins did nothing at all. Seems as though they do since the phase thinggie didn't cancel out completely.

    Only thing that remains is error-checking. Review everything you've done to make those two exports to rule out some weird mistakes or glitch.
     
  12. TheJackAttack

    TheJackAttack Distinguished Member

    I attribute the difference to the plugs and hem not being completely bypassed. I'll try to make some screenshots later if I get time during baby nap and if my memory works today. I had trouble coming up with glide bolts and agraffes a minute ago speaking with another piano tech so all bets are off :-(

    Long story short is that your plugs are still partially active.
     
  13. TheJackAttack

    TheJackAttack Distinguished Member

    Something that would be helpful is if JMM could make screenshot of Cubase with plugs present and another one showing then bypassed.
     
  14. jmm22

    jmm22 Guest

    I suppose I could get screenshots if you really think it's necessary. But the bypass switch is not too difficult to know or describe. Cubase even gives a little text line describing the button's function if you just hover your cursor over the switch. On Cubase, it turns yellow when pressed, thus indicating bypass, and it is comfirmed by hearing the effect vanish from the audio. There appears to be no gradation of partially active or bypassed, and one would surely expect it to be an all or nothing option. Now there is something else to consider. There is another button that deactivates the plug in. I think I will have to run the experiment again to see if deactivating acts the same way as bypassing, or the same way as deleting. In deactivation mode, the description of the plug in remains, but turns grey.

    In any case, I am satisfied to have at least established that some kind of minor sonic effect remains when plug-ins are bypassed, as opposed to being removed altogether. When I get a chance, I will run the test with the plugs deactivated instead of bypassed..
     
  15. TheJackAttack

    TheJackAttack Distinguished Member

    The greyed out color is the goal. In my four other DAW's, one can "turn off" the fx rack but all the fx plugins show green-active. If those individual plugins are side chained somewhere else or are sending audio out to a bus themselves then turning off the original channel's fx rack won't stop a thing. Think about it in terms of wiring. Guitar comes into <Line In>. Guitar goes out <Insert Send> to compressor. Compressor goes out to eq. Eq goes out to verb. Verb goes back to <Insert Receive> but also is sent to an aux. Now it goes down the channel strip itself. By clicking bypass you may simply be cutting off the returning signal of the stick itself and not stopping the sending of the signal down the fx chain in the first place.

    This could be a result of whether you have your FX rack set up as pre fade or post fade. I'm not familiar at all with Cubase so I don't know how it defaults or it's particular routing quirks. My point is still that if the FX were bypassed for real they wouldn't affect anything.
     
  16. jmm22

    jmm22 Guest

    I follow your line of reasoning to some extent, but bear in mind that one would fully expect the monitored mix (i.e., what we are listening to) to be a true representation of what will be printed at the mixdown. When I bypass effects, the bypass is confirmed by the ear as sonic changes to the mix.

    The difference between the two mixdowns was far more subtle than if the effects had been printed in full in the same way they are heard when not bypassed. It is as if the bypass switch bleeds maybe 5% of the full effect, just enough to be made obvious only through direct A/B comparison, as was the case when I needed to restore the mix to original form and thus did many direct comparisons. Had I not mad this mistake, there is a good chance I may have never noticed. And my mix was simple enough that I have ruled out all other things like effects sends or other routes of bleed, and the two effects were only on the Stereo bus. This remains an unexpected phenomenon.

    In other words, "bypassed for real" is apparently not a yes or no decision in Cubase. There appears to be something else called sort of bypassed, depending on how closely you listen. :tongue:
     
  17. TheJackAttack

    TheJackAttack Distinguished Member

    Definitely unexpected. This cannot be replicated with any of my DAW's and I have not assisted any other Cubase user with a similar issue. I'd maybe go check out the Steinberg forums and see if someone else has reported similar.
     
  18. TheJackAttack

    TheJackAttack Distinguished Member

    And of course it could be a faulty code writing of a plugin too. Are these those MDA plugs you downloaded last month?
     
  19. jmm22

    jmm22 Guest

    They are not MDA. They are Bootsy and Kjaerhus plug ins. I like them both, although I am buying a well regarded mastering plug in very shortly, as the Kjaerhus classic limiter cannot compare to commercial mastering plug ins.

    I may try to replicate the phenomenon with stock Cubase plug ins, to determine if code writing is a factor. I suppose I could also run the John Todd's difference experiment one plug at a time, to see if it's just one or the other. It's a question of how much time I want to invest in investigating. But then perhaps some other industrious and interested Cubase user might also take up the cause. :smile:
     
  20. TheJackAttack

    TheJackAttack Distinguished Member

    I'd do it if someone wants to buy me a license for Cubase. I have to draw the line at four DAW programs.
     

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