Jay2U
Good Vibe Sponsor
- Joined
- Jan 9, 2018
- Messages
- 504
- Reaction score
- 531
- Age
- 64
A few years ago I performed a quick test to find out about the playback quality of MP3 and YouTube. In order to keep things simple, I generated a 600 Hz square wave. Square waves consist of the fundamental frequency plus all odd harmonics. The amplitude of each harmonic with regard to the amplitude of fundamental wave, is the reciprocal value of the number of the harmonic. So the amplitude of the third harmonic is 1/3, of the fifth harmonic 1/5 and so on. If all harmonics (say up to 20 kHz) are present, a neat square wave will be the result. If some harmonics are left out or have an incorrect amplitude, the wave will look distorted.
I recorded the 600 Hz signal with a digital recorder which produces a 16 bit uncompressed wav-file. Then I converted this to a high quality 320 kB/sec MP3 file. I also uploaded the original signal to my YouTube account and downloaded it from there. Hereunder the results can be seen, as captured with Audacity. The difference can be heard, even with speakers or headphones of lesser quality.
I recorded the 600 Hz signal with a digital recorder which produces a 16 bit uncompressed wav-file. Then I converted this to a high quality 320 kB/sec MP3 file. I also uploaded the original signal to my YouTube account and downloaded it from there. Hereunder the results can be seen, as captured with Audacity. The difference can be heard, even with speakers or headphones of lesser quality.