Sterero Imaging

Discussion in 'Microphones (live or studio)' started by elpezpr, Jun 15, 2007.

  1. elpezpr

    elpezpr Guest

    Hi. I've been working for a while with an AMS Logic board. It has a great feature on the main bus. It has a STEREO-WIDE setting wich "opens or closes" the stereo field. How can I achieve this in a Pro Tools system with an analog board? Does anyone know the process involved in this? I've seen this in mastering studios as well.

  2. IIRs

    IIRs Well-Known Member

    Oct 23, 2005
    You need a mid / side matrix.

    I can't tell you specifically how to do it in pro-tools (I'm a Tracktion user: its dead easy in Tracktion!) but the process is really quite simple.

    1. Add your left and right signals together to create a mono sum. This is your "mid" or "sum" channel.

    2. Invert the polarity of the right channel and mix this with the left again. The result is your "side" or "difference" channel.

    3. Route the mid channel to the mix bus, panned centre, with 6dB of attenuation.

    4. Split the side signal down two channels. Route both to the mix bus but pan one hard left, then invert the polarity of the other and pan it hard right.

    You can now adjust the stereo width of the mix by adjusting the level of the "side" signal: any higher than -6dB will widen the mix, any lower will narrow it.
  3. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    And when you get it to its widest state, it will be 180° out of phase and will completely disappear when your stereo signal is collapsed to mono. Also frequently referred to as a "vocal removal" technique for your own home made karaoke from original recordings.

    Getting wider at 51 1/2.... I mean... WISER!
    Ms. Remy Ann David
  4. DrGonz

    DrGonz Active Member

    Jun 24, 2007
    Phoenix, AZ
    Especially dont do this if.....

    Dont try that at home if u use mid-side on the mix tracks you'll lose the mid-side part of the mix quick....
    However, my bro showed me a way to create a user defined stereo image effect.
    the Idea is similar to IIRs
    I He would create STEREO premaster mixdown Then he would mix(premaster) it down again using six copies of the stereo tracks....

    II He used tracks 1/2 for the main unfiltered stereo mixdown and turned down the tracks master fader so it was peaking around -6 or something of that magnitude

    III The idea for the four remaining tracks (3-6) is to pan 3/4 hard left and then pan 5/6 hard right. Then invert tracks 4/5 and this creates a midside with a balanced approach.

    tracks 3/4 (left channel panned hard left) are one inverted mid-side
    stereo and a balancing normal stereo track turned down to -9 to -12 or so

    the same was done for tracks 5/6 (right side) turned down to -9 to -12

    Basically, this is very much like using a plugin to create a stereo image, but I have to tell ya it sounds really good still. When I use the S1 waves plugin it sucks alot of low end out of the mix, leaving my mix sounding hollow.
    My new concept towards enhancing stereo images is mostly being done in my mixing tho. I wonder how u can use this in mastering????.....
    I also use a spectral analyzer on every instrument individually as to see the midside part of the graphic.
    Well I hope any of this makes any sense at all, its all experimental for me right now, but its interesting as hell!!!
    :-? its not enough that we have to play, record, mix, master we also have to create a fake room that sounds real :p
  5. philsaudio

    philsaudio Active Member

    Apr 23, 2003
    Using WAVES S1 for this.

    Waves S1 plug in does this for you.

    Put the MS- S1 splitter up on the top part of the insert tree of your DAW
    Put a stereo plug(s) in next
    Put the MS-S1 combiner up last to combine the signals again.

    Now the left side of the stereo plug(s) are the mid or middle of the mix and the right is the sides. If you take a little of the mid frequencies out of the mid (left) side of the EQ and put them back in on the sides (right) the soundstage begins to widen.


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