For each song there are four plots. Left is the original .wav for reference. First row is a frequency range analysis over the
wohle piece, second row is a spectral (often referred to as voiceprint) view of the file. While the frequency range analysis shows the overall frequency
response of the encoder and shows errors in stereo separation, the spectral view shows accuracy. Low sound levels are of dark colours, higher levels are brightly coloured (red to yellow to white).
In spectral view, the workings of the psycho-acoustic model used in mp3 encoding are quite visible - removing most of the lower sound level frequencies of a signal if a louder set of different frequency(s) is present.
Click on the images to retrieve an unscaled version of each screenshot in .png format.
"Scherzo (Allegro Vivace)" - Ludwig van Beethoven, Symphony no. 3. [Hörtest-CD, stereoplay].
"Walking on the Moon" - The Yuri Honing Trio. Original by Sting. [Hörtest-CD, stereoplay].
"Kassensturz" - Sigi Schwab and Percussion Academy. [stereoplay highlights collection].