Latest post Wed, Apr 15 2015 12:54 AM by jef. 4 replies.
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  • Mon, Apr 13 2015 4:59 PM

    • jef
    • Top 50 Contributor
    • Joined on Sun, Feb 26 2006
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    Audio Mixdown error?

    I start with a stereo sequence, -20 tone on A1 and A2, A1 panned L A2 panned R.  Meters show -20. All good.

    I select both tracks and do a audio mixdown To Sequence - Mono to A3.   The level of the newly created audio now on A3 panned L is +6 higher than it should be.

    If I do the exact same steps and do a mix downn to Dual Mono to A3 and A4, levels are correct.  But the two tracks are not a mono mix down of the stereo.

    I must not understand how this is supposed to work, or something is broken.

    Jef

    Avid DS 11.0.2 R.I.P | MC "Well, it depends ..." mostly 8.12.9|OS 10.14.x - iMac Pro 2019 - home system MacPro Dual 2.8 8core GTX680 "Harpertown"... [view my complete system specs]

    _____________________________________________

    Jef Huey

    Senior Editor

    Old Stuff  http://vimeo.com/album/3037796

  • Mon, Apr 13 2015 10:15 PM In reply to

    • NinaLu
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    • Joined on Fri, Jul 12 2013
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    Re: Audio Mixdown error?

    You are combining tracks when you mixdown two tracks to one mono track, so the level will increase.

    According to this source it is supposed to be 6db which is what you got:

    "In fact if you combined two identical tracks, the signal level would exactly double, leading to an increase in peak level of 6 dB."

    http://manual.audacityteam.org/manual/o/man/mixing.html  (bottom of page)

     

  • Tue, Apr 14 2015 1:39 AM In reply to

    • jef
    • Top 50 Contributor
    • Joined on Sun, Feb 26 2006
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    Re: Audio Mixdown error?

    I should have been clearer.  Our mixers, using Nuendo, expect a mixdown tool to do the appropriate -6 ajustment as part of the procedure.  I do as well - and that may be the issue.

    I seemed to remember that Avid did that in the past.  Maybe my memory is faulty and you have always needed to adjust the gain manually somewhere along the line.

    I guess I was really asking, "Has it always been this way or has it changed recently?"

    Thanks,

    Jef

    Avid DS 11.0.2 R.I.P | MC "Well, it depends ..." mostly 8.12.9|OS 10.14.x - iMac Pro 2019 - home system MacPro Dual 2.8 8core GTX680 "Harpertown"... [view my complete system specs]

    _____________________________________________

    Jef Huey

    Senior Editor

    Old Stuff  http://vimeo.com/album/3037796

  • Tue, Apr 14 2015 4:29 PM In reply to

    • NinaLu
    • Not Ranked
    • Joined on Fri, Jul 12 2013
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    • Points 320

    Re: Audio Mixdown error?

    Ah, I see... that I don't know.

  • Wed, Apr 15 2015 12:54 AM In reply to

    • jef
    • Top 50 Contributor
    • Joined on Sun, Feb 26 2006
    • Maryland
    • Posts 3,726
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    Re: Audio Mixdown error?

    Ok, a bit more on this.  I had a long discussion with our senior audio mixer. 

    He explained to me that a stereo clip panned full L and R, when summed to a single, mono track would show a +3 db gain increase, assuming that the resulting clip is panned center.  This additional gain must be reduced to keep the stereo and mono mixes equal in volume.  He also said that while many audio system might have a method for creating a mono clip from a stereo mix with corrected gain, not all do and most mixers just set up various submixes to handle this chore.  So while he said he would have expected the mono mixdown to do a gain reduction, he would not hold it against it for not doing so.

    All that said, when I showed him what using the Dual Mono mixdown tool did, he was baffled and could think of no use for it based on the results we saw.

    Jef

    Avid DS 11.0.2 R.I.P | MC "Well, it depends ..." mostly 8.12.9|OS 10.14.x - iMac Pro 2019 - home system MacPro Dual 2.8 8core GTX680 "Harpertown"... [view my complete system specs]

    _____________________________________________

    Jef Huey

    Senior Editor

    Old Stuff  http://vimeo.com/album/3037796

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