Help: Stereo image manipulator - Stereo Tool 2.10

The Stereo Tool stereo image manipulator offers some unique options. The following settings and sliders are available:
  • ON
    Turns the stereo image manipulator on or off.

  • DIFF
    If ON, plays the difference between the input and output signal. Useful for analyzing the effects of different settings.

  • fix phasing (azimuth)
    These sliders can be used to repair phasing errors (AZIMUTH errors), which are often present in tape recordings, and also on some cheap CDs. Phasing problems causes playing a recording in mono or through a surround system to result in very ugly artifacts. But even normal stereo playback may sometimes sound a bit unpleasant.
    The phasing offset is automatically detected and removed by this filter.
    • max is the maximum tape head displacement (assuming cassette tapes) that can be detected and resolved. Setting it to 0 disables this filter. Suggested value: 40.
    • diff is the maximum speed at which the filter follows detected phasing errors. Suggested value: 0.20.
    For more information and a more detailed description of the sliders, see Help: Tape Restore Live!: The AZIMUTH filter.
       Stereo Tool Winamp plugin - Automatically repair AZIMUTH phasing

  • phase
    Stereo phase multiplier. Moves between 0 (no phase differences between the channels), 1 (normal phase differences, ie. no changes) up to 8 (8 times as much phase difference as in the original signal).
    0 is VERY useful for converting to MONO, the resulting sound can be downmixed to mono without any distortion or loss of sounds, as occurs with normal stereo to mono conversion. This creates a much fuller and undistorted mono sound.
    Note that "0" does not mean that the output signal is mono, because the instrument locations are not affected by the phase slider. To get mono sound, also put the width slider to 0.

    When playing compressed audio, especially lower (< 192 kbit/s) bandwidth MP3 files, setting phase to a high value will very strongly amplify the already present MP3 encoding artifacts, which results in a very poor sound quality.

  • width
    Stereo width multiplier. Moves between 0 (all sounds in the center, 1 (no changes) up to 8 (the sounds are moved 8 times further away from the center than in the original signal, if possible of course).
    Note that "0" does not mean that the output signal is mono, because the phase differences are not affected by the width slider.

    Setting width to a very high value will almost always introduce artifacts, so it should be used carefully.

    Use phase and width with care: High values can cause annoying artifacts, especially if both values are high.
    As a rule of thumb, keep one of the sliders at (or below) 1.

    Some example uses:
    • Goal: Mono output.
      • Set phase and width both to 0. This results in mono sound, but without the loss of sounds and distortions that normally occur when converting from stereo to mono.

    • Goal: Stronger stereo effect.
      • Set width to 1 and phase to 2-3 (lower if using MP3 recordings). The instruments stay at the same position, but the phase differences are increased, which usually results in a very pleasant sound.
      • Or: Set phase to 1, width to 2-3. This way the instruments are moved further apart. Note that this masks some of the phase differences.
      • Or: Set both phase and width slightly above 1.
      In my opinion, the first option clearly gives the best result.

    If there is a phase difference in the bass between the left and right channel, and the sound is played using a single bass speaker, the bass will get deformed and lowered in volume. If this filter is turned on, phase differences for bass sounds are removed completely, which solves this problem.
    This occurs only very rarely. Note however that when the "phase" slider is set to a high value, this will occur much more frequently.

  • angle
    This slider can be used to add a phase offset between the channels. Both -180 and +180 cause the channels to be the opposite of each other, 0 is normal output.
    Note: The phase slider is performed first!

  • stereo only
    -100 %: Play ONLY the mono sounds.
    0 %: Don't do anything
    +100 %: Play ONLY the stereo sounds.
    If an instrument is only present on one channel, -100% will completely remove it. If an instrument is present at the center, +100% will completely remove it.
    Note: The width slider is performed first!
    Use 'stereo only' with care: High values can cause annoying artifacts.

The bars display the input and output phase and width. Use these bars to visually check the effects of what you are doing.

Stereo Tool Winamp plugin - Stereo image manipulator

Stereo Tool 2.x     (C) Copyright 2006 by Hans van Zutphen     Email: software@hansvanzutphen.com