Accidental Phase Cancellation When Faking Stereo Guitar Tracks

Discussion in 'Recording In Progress' started by 3-Chord-Genius, Jun 4, 2020.

  1. 3-Chord-Genius

    3-Chord-Genius Poster Extraordinaire

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    Many of you are probably familiar with the process, a process I discovered by accident and found quite useful. You want to record a guitar track with a stereo image, and to save time you simply record one guitar track, copy it to another track, pan the two hard left and hard right, then bump one slightly ahead of the other.

    The result is a good stereo image in headphones, but occasionally I noticed that I lose the stereo image and it jumps to the center. I noticed this affect only happens in headphones, and different sets of headphones exhibit the effect differently. My uneducated guess is that this is Phase cancellation taking place.

    Has anybody else encountered this?
     
  2. Frodebro

    Frodebro Doctor of Teleocity Ad Free Member

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    The signal becomes mono because the two tracks are realigned at that point, not phase cancellation.
     
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  3. 3-Chord-Genius

    3-Chord-Genius Poster Extraordinaire

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    Is that the case, though? I ask because it only happens intermittently, and since one track is completely bumped ahead of the other one, I'm wondering if the bump was so slight that the waveforms reaching the ear are inverse for a moment or two.
     
  4. AAT65

    AAT65 Friend of Leo's

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    I imagine that it is because — completely by chance — there are points where the delayed signal happens to be identical to the original: phase reinforcement rather than phase cancellation.

    I would suggest you change the EQ on the delayed channel too. That would hopefully reduce the chances of this accidental re-alignment. The way the old ‘mono reprocessed as stereo’ trick was usually done was to EQ one channel to be very bass-heavy and the other to be very treble-heavy, iirc. When I’ve done this trick with vocals recently I left the original track as was and put quite a heavy bass and treble cut on the delayed track. Alternatively you could maybe add some light modulation to the delayed track.
     
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  5. Steve 78

    Steve 78 Friend of Leo's

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    I've never encountered it. How far are you bumping ahead? I've usually used about 10-20ms.
     
  6. Biffasmum

    Biffasmum Tele-Meister

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    Unless you have inverted the phase of one track the effect would be additive so not phase cancellation. Panned hard left and right with no delay you’d end up with guitar being centre and 3dB louder.

    Independent fx on the tracks, including say a variable delay on one will probably help prevent the mono outcome it sounds like is happening.

    Happy fiddling!!
     
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  7. TokyoPortrait

    TokyoPortrait Tele-Afflicted

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    Hi.

    Try something to mess with the pitch on one track too. I’ve read that people will move it up to 10 cents.

    For what it’s worth, I quite like the Waves Reel ADT plug-in. It does all this stuff for you. Other brands will too. Variable delay and pitch shifting and whatnot.

    Pax/
    Dean
     
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  8. Norris Vulcan

    Norris Vulcan Tele-Afflicted

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    Mid/Side is an option:
    [​IMG]
    Or just sending your mono track to a stereo bus for processing.
    Or re-amping...
     
  9. Biffasmum

    Biffasmum Tele-Meister

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    Dean is right that pitch and modulation will help your stereo ambitions.

    You can get really creative by having multiple fx, maybe gates or dynamics triggered by other instruments via a key or side chain input, maybe a hi-hat.

    You could even double track it or add another guitar part of course :)
     
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  10. TokyoPortrait

    TokyoPortrait Tele-Afflicted

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    Hi.

    Yeah, that’s what I tend to do, just straight up double track it.

    Mind you, everything I do is as rough as guts, and my songs are simplistic drivel. Double tracking the guitar part in my case is almost like adding another guitar part, that’s how divergent my best attempts can be :)

    If you are capable of subtle, intricate or complex, demanding playing, accurate double tracking might be time consuming and problematic. In that case, some form of ADT might be best.

    Pax/
    Dean
     
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