tk_speaker - the first measurement


What you need

Step by step

  1. switch off any sound servers (e.g. arts or esound...) or choose a window manager without a sound server (e.g. fluxbox)
  2. set the soundcard's master output to 80% (with the mixer program of your choice e.g. rexima or kmix)
  3. the same for the line-in input
  4. select line-in as recording source
  5. start tk_speaker and check the correctness of the audio device (under menu: Configuration)
  6. choose as measurement: "Measure with a chirp signal"
  7. the parameter should be:
    • Start frequency: 20
    • End frequency: 20000
    • Count of stimulus blocks: 6
    • Silent blocks before stimuli: 0
    • Silent blocks after stimuli: 1
  8. press the start button

Your result should be similar to this:

tk_speaker screenshot

This shows the recorded stimuli under NetBSD. There is a unwished break (from app. 0.1 to 0.15s) in the record. This is always happend when the play/record buffer of the soundcard is the first time empty (no idea what's the reason for this behaviour?!). But tk_speaker can blank out this error.

The frequency response

You should get something like this:

The frequency response picture

I wish you a good time



Last change: 10. February 2009