[linux-audio-user] Mastering; Rezound, fir filter, digital clipping

Hi, I'm doing a study on audio mastering. Hopefully this letter will generate some correspondance from which I'll learn enough to augment a GFDL licensed document that I've been working on. The test job is an album I recorded several years ago. The source I've decided to use is 16bit 44100 audio CD. I'm restricting the applications I use to jack clients. I guess the process of copying audio and data from CD doesn't introduce any opportunity to compromise the sonic quality of the source. Am I right or wrong? Having opened the songs in Rezound, I've discovered that some of the songs have an inordinate amount of clipping--represented by vertical red lines on the time line. For the purposes of testing this is excellent because they're an opportunity to solve a common problem. The clips cause a series of questions for which I absolutely do not have definitive answers. Is what I am seeing clipping or is there a more accurate term to describe what I'm seeing? Perhaps someone could provide a technical explanation of clipping or a link to a definition. What tools do you use for eliminating clipping that already exists in a source? I don't care at all about preventing the problem. For the moment I am using the Rezound Arbitrary Fir Filter to identify the hz where the clips occur and am performing a decibal cut on the problem range. The interface for this filter enabled me to do some detailed work. Reguardless of how detailed I get, there's an audible consequence to eliminating the clips. I configured a preset with the minimal settings required to eliminate the clips but the result is audibly unacceptable. Another preset eliminates about 80% of the clips and audibly is marginally acceptable if applied to the entire file. What's interesting about this specific set of clips is that they are mostly inaudible. The clipping occurs around 10kHz -> 15kHz and are almost all within the high hat. This causes me to wonder: *how Rezound is configured to conclude that there are clips *should measuring for these types of problems be user configurable or does a technical specification define when a clip occurs *can engineers safely ignore inaudible clips and tell their clients that there's room to fudge and not to worry Is a Fir filter a good tool for addressing the problem of digital clips or is there something better? Are there alternative Fir filter algorithms that produce better results than the one being used in Rezound? I haven't a clue what Rezound uses. Anyway, there's a few of my questions which I realize are probably enough to exhaust anyone's patience. Reguardless, I really would appreciate your thoughts. ron __________________________________ Do you Yahoo!? Yahoo! Calendar - Free online calendar with sync to Outlook(TM). http://calendar.yahoo.com