Convenience over SQ, right?
Bits Are Bits, Right?
So I'm currently heading down the path of exploring which CD-Rs sound best in my CD player, along with what burn speeds sound best and what CD burners make the best CDs. I already know from my research that the more accurately the pits are placed on the CD (e.g. less jitter in the recorded data), the better chance I stand at getting the CD to sound good. There is a counter-argument to this idea that goes something like this: "Bits are bits and as long as the CD player can read them, the accuracy of the spacing doesn't matter because everything is thrown into a buffer which removes the effect of any jitter written into the data during burning." I know I don't agree with that logic, but for the life of me I can't remember the technical reasons. I know I used to know. Haha!
So who here knows why buffers don't solve all of our problems in the digital realm? How come timing accuracy matters in the stages before the data buffer?
So who here knows why buffers don't solve all of our problems in the digital realm? How come timing accuracy matters in the stages before the data buffer?
Showing 8 responses by geoffkait
almarg As I see it the reason is that what is happening before the buffer, which is dependent on the physical characteristics of the particular disc, is affecting circuitry that is after the buffer. That is the basic point Kirkus was making in his 2011 post that I quoted above. Those effects are not occurring via what he refers to as the "forward signal path," meaning the intended signal path that we tend to think of, but rather via coupling of noise via unintended pathways. Those would potentially include grounds, power supplies, stray capacitances, or even the air. Such effects will of course vary depending on the design of the specific component. >>>>Is there a Babel Fish translator for that? addendum: if it doesn’t make sense it’s probably not true. |
mkgus Last night I copied one of my favorite CDs to a black CD-R and the difference in sound quality between the 2 discs was quite apparent. The treble was much more laid back and “tamed.” I could hear micro-details better. It’s too early to conclude which version is better as they both have their pros and cons. I’m interested in the “why.” Does one disc have more read errors than the other? If not, then I conclude that the way the data (the exact same data, that is) is arranged on the disc matters. The precision of the pit spacing, the width and depth of the pits, and the material of construction of the CDs may play a role. If it’s all the same data and the read errors are minimal, then what is happening before the buffer is having effect on the sound. >>>>>There are a number of possibilities. One is that the copy routine was copy til perfect. Another is that the laser reads black CD-Rs better than standard silver CDs. It could be there’s less laser light scattering in the black CD-Rs. Just as 24 it Gold CDs have higher reflectivity than silver CDs and usually sound superior. One reason SHM Super High-Performance Material CDs from Japan generally sound superior is the clear layer of the SHM CD is more transparent to the laser than plain old polycarbonate which is only about 91% transparent. Less light scattering. Better optical signal to noise. It’s possible the clear SHM material is stiffer than ordinary polycarbonate and that the CDs are more perfectly round. Another more far out possibility is that copies just sound better, period. Copy an LP to tape, copy a CD to CD-R, copy a CD to tape. No one knows why. The spacing between pits and lands varies, they represent a series of “words” of variable but specific meaning, the length of pits and lands themselves is also variable. the details are specified in the REDBOOK standard. The geometries involved with depth of pits is also specified in the REDBOOK. The system won’t work if the geometries are not absolutely correct as the laser light beam cancels itself out by wave interference when it strikes a pit. That’s why there is no return light signal for pits, only for lands. |
mtdining Unfortunately, our brains sample 10x more frequently than cds...vinyl is best. >>>>>I’m from the future. When the CD is played on a CD player not (rpt not) encumbered with all the problems CD players have had since the very beginning, CD has much more detail than vinyl. It has always been right there on the CD. You just couldn’t hear it completely or accurately, that’s all. You don’t even have to play 20 bit or 24 bit CDs. 16 bit Redbook CD will do just fine. It’s the player, you can forget about everything else. In the future there is no more glare, no more congealed midrange, no more weak bass, no more two dimensional sound, no more thin paper mache sound. |
mkgus OP Yes, digital only exists as a mathematical concept. All of reality is analog (at least the reality we deal with - at the scale of Planck time and Planck lengths things may be different). A stream of “digital” data is an analog signal that a computer has to interpret as a 1 or a 0 by deciding when the value has changed enough and at what time to be interpreted as a different bit. >>>>No, actually reality is more like digital. At the quantum level, which is really where the rubber meets the road let me remind you, gentle readers, that everything can be described by its quantum state; electrons have certain quantum states and require a certain amount of energy to get to the next level/orbit. That is more like Digital than Analog, I.e., having non-continuous states. In an analog world the electrons would not have non-continuous orbits. Light also is described by quantum states. To whit, “The photon model accounts for anomalous observations, including the properties of black-body radiation, that others (notably Max Planck) had tried to explain using semiclassical models. In that model, light is described by Maxwell’s equations, but material objects emit and absorb light in quantized amounts (i.e., they change energy only by certain particular discrete amounts). Although these semiclassical models contributed to the development of quantum mechanics, many further experiments[3][4] beginning with the phenomenon of Compton scattering of single photons by electrons, validated Einstein’s hypothesis that light itself is quantized.[5]” |
It all comes down to a couple things: the scattered laser light gets into the photodetector as noise, the CD player is susceptible to external and internal vibration, the CD itself flutters during play so much that the laser servo system can’t keep up. The Reed Solomon Error codes are practically worthless. There is no buffering in most CD players. All the King’s horses and all the King’s men couldn’t put Humpty Dumpty together again. |