Out of phase stereo test tone

I know this is probably rudimentary, but I am new to Audacity and I can’t get it done. I want to create a stereo 1K test tone with one channel 180 degrees out of phase of the other.

Here you go

Windows playback “audio enhancements” can introduce cross-over between left & right channels

[ There can be a second layer of audio-enhancements which need to be disabled. ]

Thank you very much Trebor. Is there a way to increase the output? I get 37mv from the clip. I need more like 1v.

Run the Amplify effect. 0dBFS is the “digital maximum” and it will default to that.

The actual voltage depends on your soundcard (or amplifier or whatever). A full-volume line-level or headphone-signal will be in the ballpark of 1V.

To flip the phase/polarity of one channel:
Split Stereo Track allows you to edit/process the left & right channels separately.

Select one of the tracks, then Effect → Special → Invert.

“Teach a man to fish…” :wink:

One way is to use the Nyquist Prompt:

  1. Create a new stereo track (“Tracks menu > Add New > Stereo Track”)
  2. Open the Nyquist Prompt effect
  3. Copy and paste this code into the Nyquist Prompt and run it:
;type generate

;control HZ "Frequency" int "Hz" 1000 0 10000
;control GAIN "Amplitude" float "" 0.8 0 1
;control LPHASE "Phase left channel" int "degrees" 0 -180 180
;control RPHASE "Phase right channel" int "degrees" 180 -180 180
;control DUR "Duration" int "seconds" 30 1 300

(if (= (get '*selection* 'channels) 1)
    (print "Error.\nA stereo track must be selected.")
    (let* ((pitch (hz-to-step HZ))
           (left (osc pitch DUR *sine-table* LPHASE))
           (right (osc pitch DUR *sine-table* RPHASE)))
      (vector left right)))

Thanks Steve. This is just what I needed. I was able to adjust my equipment with your tone generator. Much appreciated.

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