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(kinda stupid) Stereo Question

Discussion in 'Recording' started by Jeemy, Feb 9, 2005.

  1. Jeemy

    Jeemy Well-Known Member

    I was listening to a mix of a narration on headphones the other day, and the vocal panned from dead centre, to coming from the left and right side into both ears but with no centre image.

    Make sense? I thought about this a bit more and either I have a mental block or I'm left thinking how the hell do you do that?

    Can it be done on speakers? Is it just psychoacoustic - you here the 2 tracks pan outwards and when they stop, you assume there is no centre left?

    Anybody know what I am on about?
     
  2. JoeH

    JoeH Well-Known Member

    Not quite sure what you're describing Jeemy, but it sounds like it could be accomplished as easily as using three mics during the VO recording...

    Record the narrator the entire time with all three mics on separate tracks: a center (cardioid) mic, as well as two wide-image (L&R) mics; ORTF or perhaps just a spaced pair - whatever it takes to get the effect you've described. (This is done a lot for big-movie VO presentations, btw., using all three mics)

    For the effect you're describing, it's not more more compliacated than starting with the center mic as the main source, and then gradually cross-fading to the two outside mics, one at a time, or together. If done properly, the sound should spread out to each side, with a bit of a "hole" In the middle, at least compared to what you originally heard with the single center mic.

    does that sound like what you were hearing?
     
  3. Kurt Foster

    Kurt Foster Distinguished Member

    It sounds to me more like something happened to the L/R phase relationship at some point ...

    If the left and right channel are completely in phase with each other and a single source (like a mic) is panned down the middle there will be a "phantom" image dead center ... as if there were a 3rd speaker between the left and right one ...

    Now, if you flip the phase of one channel out of phase .. that center "phantom" image disappears...

    You can also muck up phase relationships with reverbs or delays ... especially short ones.
     
  4. Jeemy

    Jeemy Well-Known Member

    Either is likely, I just started thinking, well, if there is a channel panned completely left, and a channel panned completely right, you'll still get the centre image, but I just heard it, so there must be a way!

    I still think 2 mics panned hard L/R will leave no hole, and although this was emphasised by the cans, it was pretty convincingly absent in the centre, so the phase thing is probably it.

    Its a good trick to start playing with methinks...
     
  5. oadamy

    oadamy Guest

    if im understanding what your describing correctly, it can be achieved with delay. double the vocal track onto two channels, one panned hard left the other hard right, then put a delay (i usually use 10-15ms) on one side. delay in the true sense of the word. this "spreads" it out.

    the trick sounds best through headphones. sometimes the out-of-phaseness can sound really ugly though.
     
  6. Kurt Foster

    Kurt Foster Distinguished Member

    What will happen with a short delay like 15 ms is the sound from whichever channel is not delayed ... will appear as the loudest and therefore the sound will appear to be panned to that channel ... You have to turn up the track that is delayed to get things to sound as if they are down the center ... and then you have a stronger signal (on the meters) on the side that was delayed ...
    This is because the human brain always percives the sound that arrives first as the loudest... This is how we derive our directional cues in nature. This is known as the haas or precedence effect.

    http://www.sfu.ca/sca/Manuals/ZAAPf/h/haas_effect.html

    The Haffler effect

    Another interesting thing to mess with ...

    Take a wire from the postive side of one speaker and the negatve side of the other speaker ... and run them to another speaker, set up behind the listening postion ... See what you get ... Lots o' laughs.
     

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