El said: "In Sean's explanation the second set of 20 dots in set B should not be random. Those dots should lie somewhere between the two dots adjacent to them".
By placing the "extra" dots ( sampling points ) "mid-point" between the previously adjoined dots, the end result would look MUCH smoother and far more predictable. While this "could" be the case if playing back sine waves of varying amplitude and duration, music is anything but "sinusoidal" by nature. There are very rapid peaks and dips that take place, sometimes completely changing the direction that the signal was previously headed just a split second previous. These peaks and dips can can switch randomly back and forth across the "zero line" or they can remain above or below the "zero line" for extended periods of time. On top of that, these waveforms may not be symmetrical at all i.e. much bigger peaks on the positive side than there are dips on the negative side or vice-versa. It is for this reason that "industry standard test tones" aren't quite as revealing as we would like as far as revealing how a component performs during normal use reproducing musical waveforms. This is why several different types of tests have to be used in order to obtain any type of meaningful relationship between test bench performance and real world performance.
If music was more like a sine wave i.e. with predictable amplitudes, polarities and durations, error correction algorithms could be much simpler and far more accurate. However, musical notes are anything but predictable in terms of amplitudes, polarities, durations or patterns. As such, the potential to read an error from anything but a perfect disc is not only high, but the potential for further errors to take place when data is lost and the machine is trying to "fill in the blanks" becomes even higher.
Somewhere in one of the old IAR's ( International Audio Review ), Moncrieff covered quite a bit on the flaws of how "Redbook" cd was designed and how their "error correction" and / or "interpolation" techniques were far from all-encompassing. Then again, this was all newer technology at the time, so they were kind of winging it as they went along. As such, the potential for a newer, much better digitally based format is definitely there, especially if we learn from past mistakes and take advantage of the more recent technology that we have.
Germanboxer: As far as certain manufacturers supporting / slagging specific design attributes, did anyone ever expect a manufacturer to support a design / type of product that they themselves didn't already take advantage of? Would you expect a company that didn't use upsampling to say that upsampling was superior or a company that did use upsampling to say that the technology that they were using was a poor choice?
Bombay: Glad that you were able to see where i was coming from after further explanation. Hopefully, others could follow along here too.
As a side note, read the description of this DAC as listed on Agon. You'll see that the designer not only played with various types of filtering, but gave the end user the option to accomodate their personal preferences / system compatibility at the flip of a switch. Bare in mind that this unit was out long before Philips came out with their SACD 1000, which also gave users the options of various filter shaping and cut-off frequencies, etc... Sean
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By placing the "extra" dots ( sampling points ) "mid-point" between the previously adjoined dots, the end result would look MUCH smoother and far more predictable. While this "could" be the case if playing back sine waves of varying amplitude and duration, music is anything but "sinusoidal" by nature. There are very rapid peaks and dips that take place, sometimes completely changing the direction that the signal was previously headed just a split second previous. These peaks and dips can can switch randomly back and forth across the "zero line" or they can remain above or below the "zero line" for extended periods of time. On top of that, these waveforms may not be symmetrical at all i.e. much bigger peaks on the positive side than there are dips on the negative side or vice-versa. It is for this reason that "industry standard test tones" aren't quite as revealing as we would like as far as revealing how a component performs during normal use reproducing musical waveforms. This is why several different types of tests have to be used in order to obtain any type of meaningful relationship between test bench performance and real world performance.
If music was more like a sine wave i.e. with predictable amplitudes, polarities and durations, error correction algorithms could be much simpler and far more accurate. However, musical notes are anything but predictable in terms of amplitudes, polarities, durations or patterns. As such, the potential to read an error from anything but a perfect disc is not only high, but the potential for further errors to take place when data is lost and the machine is trying to "fill in the blanks" becomes even higher.
Somewhere in one of the old IAR's ( International Audio Review ), Moncrieff covered quite a bit on the flaws of how "Redbook" cd was designed and how their "error correction" and / or "interpolation" techniques were far from all-encompassing. Then again, this was all newer technology at the time, so they were kind of winging it as they went along. As such, the potential for a newer, much better digitally based format is definitely there, especially if we learn from past mistakes and take advantage of the more recent technology that we have.
Germanboxer: As far as certain manufacturers supporting / slagging specific design attributes, did anyone ever expect a manufacturer to support a design / type of product that they themselves didn't already take advantage of? Would you expect a company that didn't use upsampling to say that upsampling was superior or a company that did use upsampling to say that the technology that they were using was a poor choice?
Bombay: Glad that you were able to see where i was coming from after further explanation. Hopefully, others could follow along here too.
As a side note, read the description of this DAC as listed on Agon. You'll see that the designer not only played with various types of filtering, but gave the end user the option to accomodate their personal preferences / system compatibility at the flip of a switch. Bare in mind that this unit was out long before Philips came out with their SACD 1000, which also gave users the options of various filter shaping and cut-off frequencies, etc... Sean
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