Romy the Cat wrote:

Andy,   my mind does not operate by the categories you employ, I rather think about nature of Sound not about harmonic/non-harmonic distortions. The whole subject about the distortion is intricate, not to mention that it is not know if we in fact are able to recognize and adequately react to distortions. What I am saying that your explanation might explains something but nothing that I have practical or sensual experience with. The feeding system of sinewave tones and observation of introduced of harmonic or non-harmonic tone doe not proved to me anything about compression.  First, are you sure that the harmonic or non-harmonic problems come from compression itself but not from a wrong ways to inflict compression? You saddest to take my favorite digital compressor and set it up for some 'reasonable' amount of compression. Are you sure that in this case the sound will be ruined by compression but not by the DSP processing or by somthing else? Second, if you subtract the source from output during your “feeding system” experiment and hear juts distortions without the souses then what will you hear? I know what you will be hearing but the question is what would you be hearing that would allow you to make a cultural judgment about Sound? The answer is nothing. Therefore I do not tend to think about sound as compellation of original sound and distortion but I rather look at the whole sound, and I really know what to look for. Therefore I think that the proof in the pudding and what I observe is that a right amount and properly applied compression do not hurt sound, and in some cases very much improves it perception. Now, what would be the “right amount” and the “properly applied type” I have no idea. The caT

As things stand today, I believe that the biggest gain in quality is not to be had via the pursuit of higher resolution formats.

A friend of mine who works for a large media distribution business (like Amazon) recently gave me a bunch of sample CDs that were left over from previous evaluations in their listening room. Record labels regularly send these samples out to large retail operations hoping to secure an order. Many of the CDs are bare, with no cover art, and have only a simple hand written title for purposes of ID. Most have a word saying something to the effect that the material is "not for resale". Listening to these recordings revealed in all cases a total absence of dynamic compression; they actually sound really good.

This is somewhat surprising, as I would have thought all mastering to have been done before issuing even the pre-sale samples, but apparently not, or apparently there are two versions (one compressed and one not). In any case, I interpret this finding as an admission on the part of the labels that the effects of dynamic compression are in fact detrimental, and that people running the labels are completely aware of the damage it does.

Though the material on newer (purchased) CDs seems to have less dynamic compression than was the case with CDs from about 3 years ago, it is still present and widely used, and I fully expect that the commercially available versions of these samples will receive the compression treatment.

This I just do not understand... The original motivation (mastering a recording to sound louder than offerings from competing labels when broadcast over the radio) is no longer valid; as a result of this practice (dynamic compression to increase perceived loudness), broadcast signals are now processed before diffusion such that perceived loudness is held at a constant level. Unless I am missing something, there is no longer any reason to continue the practice of dynamic compression; I just don't get it !

The only possible motivation I can imagine is in the context of an individual listening to music files in a noisy environment (an MP3 player used in the subway for example); such a user might "benefit" from dynamically compressed files where the quiet passages are boosted. So is that it? Is this what's dragging down the quality for all users? There has got to be a better way!

jd*