Testing the Radio shack stereo microphone (33-3028) for self noise

(Using pillow technique suggested by Walter Knapp)

Here is the sound spectrograph of a combination field recording and a recording made under several pillows. There is no digital filtering and I have bypassed the graphic equalizer I usually use in transferring sound files from my Minidisc recorder (MZ-R-70) to the computer . The recording was made in one continuous transfer and trimmed for brevity.


Analysis of field recording

Analysis of pillow recording

Superposition of the two analysis

I would like to see similar tests of other microphones for comparison.

Any suggestions or comments would be appreciated

Gregory Kunkel