Channel Mixer Plug-in

This plug-in allows the left and right channels of stereo tracks to be mixed and distributed between the channels of a stereo track.

Examples:

  • Mix left and right channels in equal proportion to produce a 2 channel mono track.
  • Invert left or right channel independently of the other.
  • Mix each channel with the other channel inverted (for centre pan removal).
  • Make both channels the same as the left channel, or both the same as the right channel.
  • “Widen” the stereo image by adding a proportion of the other channel inverted to each channel.
  • Pan the centre audio to the left or to the right.
  • Vocal Removal.

There are 12 presets included for quick and easy access to many commonly used functions. Alternatively the sliders may be used to create any custom channel mix that might be required.

New in version 1.1

  • A few changes to the interface which will hopefully make it easier to use effectively.
  • The default custom slider settings now set to zero
  • FAQ file added to ZIP

Download plug-in only:
Right click to save channel-mixer.ny
(For Internet Explorer “Save Target As”)

Download ZIP file including FAQ file:
Right click to save channel-mixer.ny1.zip
(For Internet Explorer “Save Target As”)

11 thoughts on “Channel Mixer Plug-in”

  1. I can’t find any controls for Channel Mixer. Are they supposed to be in the Effect menu? I am running Windows 64 bit and placed the plugin in this folder C:\Program Files (x86)\Audacity\Plug-Ins

  2. I have been using your Channel Mixer Plug-In to try to rectify a cassette-to-digital transfer that was initially recorded skewed to one channel. For my purpose, how is the Channel Mixer different from the Pan Slider feature of Audacity 2.0.3 ?
    Thanks.

    1. The Pan slider may be a bit easier to use for your purpose than the Channel Mixer plug-in because you can adjust the Pan slider during playback, which means that you can hear what you are doing in “real time”.

      The Channel mixer plug-in is more versatile and, depending on the recording that you are trying to fix, may give better results.

      When using the Pan slider, pushing the slider to one side will reduce the volume on the other side. For example; if the audio is louder on the right, you can move the slider to the left and that will reduce the level of the audio in the right channel – move it too and fro until it sounds even left and right. After making the adjustment it may be necessary to increase the overall volume, which you can do using the Gain slider (keep an eye on the playback meter so that the playback level does not exceed 0dB.

      When using the Channel Mixer effect, you can either, make the quieter side louder by increasing the gain of that channel, or you can make the quieter side louder by adding some of the other channel to the quieter channel. Because Nyquist plug-ins do not have “Preview” you will need to test different settings on short sections of the audio to see what works best (which is a bit more fiddly, but you can see the results in the waveform, which does not happen when using the Pan slider). If the original recording is a bit noisy, you may find that the result sounds better by adding some of the louder channel to the quieter channel, but note that for a stereo recording this will narrow the stereo separation (making it sound less “wide”).

      Steve

  3. Thanks for contributing this – very useful.

    I’m interested in automating the mixer. I’d like to toggle the channel left/right every time a label is encountered. This is for a project where I read a script, and one “character” needs to be on the left channel only, and all other characters on the right channel only. If I set a label at each transition point, then – in theory – something could toggle the channel.

    Ideas?

    1. Unfortunately Nyquist is not able to access label tracks.
      If you would like the functionality of Nyquist to be expanded to allow it to access label tracks you could propose it as a “feature request” on the Audacity forum: http://forum.audacityteam.org/viewforum.php?f=20

      Posting to the Audacity forum requires registration and e-mail verification (like most forums) and your post will enter a moderation queue so it will not appear immediately, but posts generally get approved within a few hours.

      A possible, but slightly awkward workaround would be to export the label track as a text file (Tracks menu > Edit Labels > Export). The exported file could then be opened in a text editor (such as NotePad) and the text copied and pasted into a text input field of a Nyquist plug-in.

      Other options to accomplish the task that you describe are discussed in this topic on the Audacity forum: http://forum.audacityteam.org/viewtopic.php?f=26&t=62821

  4. your plug in in french version ..
    for french users .!!


    ;nyquist plug-in
    ;version 3

    ;type process
    ;categories "http://lv2plug.in/ns/lv2core/#MixerPlugin"
    ;name " 2 Channel melange .."
    ;info "by Steve Daulton (http://easyspacepro.com). Released under GPL v2 Trad fr godard.\n\nchoix 'utilisateur' choisir valeurs, ou sinon presets avec valeurs programmees).\nchoix 'Debug' pour apercevoir valeurs choisies. \n\n"
    ;action "Mixing..."

    ;; channel-mixer.ny by Steve Daulton, June 2010
    ;; Released under terms of the GNU General Public License version 2
    ;; http://www.gnu.org/copyleft/gpl.html

    ;; Updated 28th September 2010
    ;; Updated 8th March 2011

    ;control preset "choix utilisateur" choice "utilisateur,Mono (50/50),Mono (seul gauche),Mono (seul droit),stereo faible,peu large Stereo,large Stereo,Extra large,Centre a gauche,Centre a droite,inverse gauche/droit,supprimer centre (g/d invert),supprimer centre(mono),inv gauche,Inv droit" 0
    ;control left-mix-L "GAUCHE CHANNEL OUTPUT \avec gauche channel (%)" real "" 0 -100 100
    ;control left-mix-R "avec droit channel (%)" real "" 0 -100 100
    ;control right-mix-L "DROIT CHANNEL OUTPUT \avec gauche channel (%)" real "" 0 -100 100
    ;control right-mix-R "avec droit channel (%)" real "" 0 -100 100

    ;; Create list of values from selected preset or from the slider values
    (setq channels
    (case preset
    (1 (list 50 50 50 50)) ; 50 /50
    (2 (list 100 0 100 0)) ; seul gauche
    (3 (list 0 100 0 100)) ; seul droit
    (4 (list 70 30 30 70)) ; stereo faible
    (5 (list 85 15 15 85)) ; peularge Stereo
    (6 (list 100 -30 -30 100)) ; large Stereo
    (7 (list 100 -60 -60 100)) ; extra large
    (8 (list 50 50 -50 50)) ; Centre vers gauche
    (9 (list 50 -50 50 50)) ; Centre vers droite
    (10 (list 0 100 100 0)) ; glisse gauche/droit
    (11 (list 100 -100 -100 100)) ; centre supprime L/R invert
    (12 (list 100 -100 100 -100)) ; centre supprime mono
    (13 (list -100 0 0 100)) ; Invert gauche
    (14 (list 100 0 0 -100)) ; Invert droit
    (T (list left-mix-L left-mix-R right-mix-L right-mix-R))))

    ; Print settings to debug window
    (format T "New Left Channel:~%Left mix = ~a %~%Right mix = ~a %~%
    New Right Channel~%Left mix = ~a %~%Right mix = ~a %~%\n"
    (nth 0 channels)(nth 1 channels)(nth 2 channels)(nth 3 channels))

    ; convert percent to +/- 1
    (setf channels (mapcar #'(lambda (num) (/ num 100.0)) channels))

    ; mix and output as vector
    (if (arrayp s) ; check for stereo track
    (vector
    (sum
    (mult (aref s 0)(nth 0 channels))
    (mult (aref s 1)(nth 1 channels)))
    (sum
    (mult (aref s 0)(nth 2 channels))
    (mult (aref s 1)(nth 3 channels))))
    ; or error if not stereo

    (format NIL "Error\nChannel Mixer demande des pistes stereo ."))

  5. OK, thanks. I downloaded Audacity 1.2.6, so that’s why it wouldn’t work. I downloaded Audacity 1.3.12 (Beta) and now your plug-in is in the list.

    Thanks for the quick reply.

  6. If you have previous had Audacity 1.2.x installed and now have Audacity 1.3.12 installed you will have 2 different Audacity program folders. Both folders will have a “plug-ins” sub folder. You need to put the “channel-mixer.ny” file into the plug-ins folder for Audacity 1.3.12

    On Windows the default Audacity 1.2.x installation folder is usually called “Audacity”, whereas the Audacity 1.3.12 installation folder is usually called something like “Audacity 1.3 Beta (Unicode)”.

    The recommended version of Audacity (until Audacity 2.0 is released) is the latest 1.3.x version (currently 1.3.12). The majority of plug-ins on this site require Audacity 1.3.x (or later).

  7. I just downloaded the latest version of Audacity. I also downloaded your plug-in and put the unzipped ‘channel-mixer.ny’ file in the Plug-Ins folder, then restarted Audacity. When I click on the ‘Effect’ tab, I don’t see “Channel Mixer” listed there. Is it somewhere else? Am I doing something wrong?

    Thanks for your help.

    1. Plug-in Effects appear “below the divider line” in the menu, so you may need to scroll down the list further. Alternatively, while the edit menu is open, repeatedly press the “C” key to cycle through all plug-ins with names beginning with “C”.

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