Problems With Joint Stereo (LAME)
Reply #52 – 2003-12-09 10:54:38
I'd like to summarise: There are 3 possibilities 1. The distortions are caused by equipment. The main part of cymbal-like sounds is in high frequencies. These frequencies are reproduced by lame somewhat inaccurate = distorted, especially if there are other sounds that would mask the distortions. If equipment amplifies these high frequencies for some reason, these distortions can become clearly audible. Another equipment-related possibility would be aliasing: 16-17.5 kHz sounds would be 'mirrored' to some lower frequencies where they are audible much better. To test it you can do this: Use the sample from this thread . It contains low volume dialing sounds and high volume 19-21kHz sweeps that should be inaudible (try at low volume first, this might damage your equipment/hearing ). If you hear something else than the dialing sounds, your playback chain needs some modification (audio player with decent resampling to 48kHz etc.) Or you could decompress the mp3 files to .wav, burn them to audio CD-R and listen on some standalone equipment / discman etc. Problems still there? ... -> 2. Your hearing is exceptional in high frequency range. There are some "how high can you hear" threads with samples for testing, but you need some good equipment/settings (test see 1.), otherwise you'll hear aliasing and think you hear 22kHz sounds. 3. At least some of your findings could be based on immagination (don't take this personal, please - it's just the only possibility left from a scientific point of view). Unless you are sure that your playback chain isn't responsible for the problems, this question is uninteresting anyway.