I asked a good friend of mine who is a recording engineer and an expert in digital audio since digital audio is, after all, his livelihood to read through the first three parts of the series. Here is what he wrote back to me:
"Wow, that was some tedious reading. I had to skim through some of it in order to get to what they were actually trying to do, so I might have missed something. But let me get to one particular part that puzzles me the most. It's the one where they convert from wav to flac, compare the listening quality, and then convert from flac back to wav and compare the quality again. There is a very basic and obvious test they could have made that would have told them if there were any differences between the original wav file and the one that were converted back from flac. Bring them both into a multitrack program such as Logic, Protools, Audacity etc, invert the phase on one of them and then play back. If the audio is identical, playback should be completely silent since the two signals would cancel each other out. If they were still able to hear some sound, that would prove that something was messing with audio integrity along the way, but if the result was indeed complete silence, that would prove, beyond all doubt, that the differences they claim to hear don't exist and that they're crackpots. So why, in such an extremely tedious and rigorous test, wouldn't they include such a simple reality check? I just finished co-producing, mixing and mastering a five song EP for this band .... they decided to offer the full quality audio files, so I ended up making both Apple Lossless, Flac, and Mp3 files so that the customer gets the link to all three. Now, that seemed like an excellent opportunity to do the test I proposed. In this case, the original master file was created in aiff format which is sonically the same as wav (both regular PCM files but with different header formats). That file was converted to wav using iTunes (where we also made the apple lossless and mp3 files). To create the flac files I used a software called Flacer. In order to do the test, I used another software, called Fission, to convert from Flac back to wav. I then brought both the files into Logic, put a phase inverter on one of them and hit play. Total Silence! So yes, these guys are crackpots." Interesting, very interesting. -- ralphpnj Lock, Stock and Two Smoking Barrels -> Snatch -> The Transporter -> Transporter 2 (oops) -> Touch 'Last.fm' (http://www.last.fm/user/jazzfann/) ------------------------------------------------------------------------ ralphpnj's Profile: http://forums.slimdevices.com/member.php?userid=10827 View this thread: http://forums.slimdevices.com/showthread.php?t=92168 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
