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In Reply to: RE: What about simply doing a file copy? posted by Quiet Earth on May 20, 2008 at 13:17:11
Actually AIFF is a file format defined by Apple. Similarly, WAV is a file format defined by Microsoft. Although some of the control formats are different, the actual audio data in AIFF and WAV files is similiar, just raw PCM samples. (The difference is the order of bytes in the 16 bit words, which differ because Motorola processors and Intel processors store arithmetic in a different order in memory.) Store bought CDs have data in a different format as defined by the Philips/Sony Red Book, although they too have the same PCM data.
If you hear differences between Apple Lossless and AIFF you might try converting the lossless back to AIFF. You should end up with the same audio data. However, while playing a Lossless file your processor has extra work to do, and it is possible for this to cause audible effects. I don't hear differences on my system when playing FLAC compared to WAVs, but both sound better than playing CDs directly. The best results come when I use cics' cPlay application, because the audio data for a complete play list has been copied into RAM memory before the music starts.
Tony Lauck
"Perception, inference and authority are the valid sources of knowledge" - P.R. Sarkar
If we can get past the semantics, can we agree that if we change the original raw PCM samples in any way, then it is possible to hear that change in the copy?
If enough people tell me that I can't hear such a change then I will accept it as fact. (At least that's what I will say from now on to keep the peace. No sweat.)
We can all agree that some changes to the PCM samples will change the sound. (Otherwise we wouldn't be able to tell the difference between Beethoven and Beatles.) On the other hand, most people would agree with me that changing a low order bit in a single sample of a loud section of music will not make an audible difference, everything else being kept the same.
Where the disagreement starts is when the low order bit in many samples starts changing (e.g. dither issues) or where different filtering techniques are used to convert the original bits into a continuous analog waveform. Disagreement gets more intense when discussing whether there are audible side effects of various implementation techniques, e.g. caused by motors, power supplies, or software. (This includes the difference between playing AIFF and WAV files, where on a given system it may be necessary to do a byte swap when playing one format but not the other.)
There are even people who believe that other possibilities exist for influencing the sound that aren't covered by these categories, but until I can find a better way of understanding what these people are saying I personally don't find their remarks useful. Perhaps in the future they will be better able to articulate their points or I will be more receptive to their statements, perhaps goaded by a few sensory experiences that do not fit my present model of reality.
Tony Lauck
"Perception, inference and authority are the valid sources of knowledge" - P.R. Sarkar
You make some excellent points Tony. Thanks for hashing this out with me. It's true that articulating my thoughts is a challenge for me. That's a big problem considering that I try to post them here. I hope my lack of writing skills doesn't completely discredit me.In the old days, when we made an analog recording, every copy of the original recording was clearly different than the original. Noise was added or the dynamic range was reduced in the copy. No one ever argued the point that the original analog recording played back on the original recording machine always sounded better than any copy. For some reason, we now believe that once we digitize the master signal, we can make a copy that sounds exactly like the original recording played back on the original machine. I'm not really convinced of that. It might be true, but I'm just not totally convinced.
You have digital recording equipment set up in your possession. Have you ever noticed that an original recording played back on the same machine that it was recorded on sounds better than your best attempt to make a digital copy? I'm sure your skills and equipment are way better than mine (I still have a lot to learn), but I'll bet that you can hear the difference between the original and the copy and you can't really explain why. There is a disconnect, a change in timing, or something, but there is a change. (I know, there I go again. *Sigh*)
BTW, this thread has really gone quite a ways. I originally posted just to say that I could hear the difference between an uncompressed music file vs. the same file in Apple lossless. Thanks for the intelligent response. I have learned a thing or two.