[vorbis] mp3-wav-cd-audio "acoustically equivalent" to wav-cd-audio ?

[Felipe Manzano]

Marshall Eubanks wrote:
> 
> >A friend of mine made the following comment in a discussion I had with
> >him that on a website we adminster we should offer
> >
> >a) WAV or maybe shorten files
> >b) Ogg as a decent reference lossy encoded version
> >
> >He's been trying to convince me that we should offer MP3 (in lieu of
> >WAV) and possibly Ogg.
> >
> >The audio files are primarily vocals
> >
> >I am not a physics guy but his statements don't intuitively feel right.
> >Maybe he has a misunderstanding which can be clarified
> >
> >Regards, Yusuf
> >----------------------------------------------------------------------
> >regarding WAV, we used to store the masters on the disk, but moved them
> >offline due to space concerns. If a user downloads the MP3 and creates a WAV
> 
> >from it, that is going to be precisely equivalent on the audio CD in
> >quality. I have tested it myself in MATLAB using spectral and phase analysis
> 
> >(I am a physics guy, after all).
> 
> IMHO, as a professional physicist, he has no clue.
> 
> MP3 is a lossy encoding. That means you lose something.
> At a low bit rate, you tend to lose a lot.
> Just try doing this at 32 kbps stereo and you _will_
> notice the acoustic nonequivalence.
> 
> Regards
> Marshall Eubanks
> 
> >
> >recite WAV -> MP3 -> WAV -> CD Audio is *acoustically equivalent* to recite
> 
> >WAV -> CD audio.
> >
> >to confirm, Perform this experiment at home (I have done so)
> >
> >1. recite to WAV. save as A.wav
> >2. encode A.mp3 from A.wav
> >3. create B.wav from A.mp3.
> >4. ask someone to burn A.wav and B.wav to an audio CD (double blind -
> >neither you, nor they, shoudl know which is which).
> >5. listen to the CD in a standard player. You will hear zero differrence in
> 
> >sound quality.
> >
> >I am NOT saying,  not to make WAV available. But I am pointing out that the
> 
> >vast majority of repackagers only want to create CDs. And that they will not
> 
> >be able to improve upon the sound quality , though it is quite possible they
> 
> >may degrade it, during their own post-processing stages. We can safely
> >assume that most repackagers will choose to go the easy route, and we can
> >easily have a note saying "true WAV masters for many audio files are
> >available for more advanced processing. Please contact Webmaster etc etc".
> 
> >
> >as an aside - there are already several excellent freeware tools which allow
> 
> >you to create playlists of MP3 files and burn them straight to audio CD,
> >doing the WAV interpolation for you directly. No such tools yet exist for
> >OGG of course, but they too will come in a year or so (the ones I have seen
> >for OGG are still quite unstable - if it doesnt come from vorbis.com, I dont
> >trust it).
i'm not saying you can trust but..       http://www.ampburn.8k.com/

> >
> >----------------------------------------------------------------------
> >
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> >
> 
> Marshall Eubanks
> 
> tme at 21rst-century.com
> 
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