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Checking access to the sound card


In order for the program to collect readings you must first check that the software in your computer is 'listening to' the desired input.  These instructions are for using the standard Windows mixer application of Windows XP; for other Windows operating systems see Control Panel, Sounds for setting up a default recording device.  If you have another mixer application then adapt the instructions for your particular program.

Start the Windows Mixer application - usually by Start/ Programs/ Accessories/ Entertainment or Multimedia/ Volume Control.  When the mixer application is running switch to the Recording controls by using Options/ Properties/ Recording.

Make sure that the desired input is enabled for either Line-in or Microphone (a tick in the check-box labelled Select) and that its volume slider is at or near maximum.

Now switch to Playback using Options/ Properties/ Playback.  Adjust the master volume slider to a level that will give a comfortable listening level.  Adjust the volume slider for the remaining controls to at or near maximum.

Connect the line-in or microphone input of your sound card to any source of audio and start PolarPlot. The audio source may be your receiver, a tape recorder, CD player or audio generator etc. Click the yellow Choose Input button on PolarPlot's screen and select eiter Line-in or Microphone to inform the program that a sound card is used for collecting readings.

Turn on the audio device and click the 'Calibrate Input' button.  If all is well you should see a series of points plotted on the screen and a number on the left-hand box above the calibrate button. Vary the line-in or microphone volume by using either external audio controls or the Windows recording controls.

If you do not see any points plotted then go back and re-check a) the connecting leads between audo device and sound card, and b) the Windows default recording device to ensure you have selected the correct input.