I remember when Sun Micro decided they could give their customers CDROM drives and save money shipping SunOS on CD rather than quarter inch tape (QIC). As I recall they were the first to do that. I also remember Eric Schmidt cringing at the price of buying a 'gold master' machine that could cut a master disk for the replication services.
Compared to vinyl, the CD would have seemed invulnerable to dirt and damage. Even more perishable? What bunkum. Every time you play a vinyl record, you're causing a very small amount of irreparable damage. Whereas I can still retrieve a bit-perfect copy of my 20+ year old CDs, even if the underside is severely scratched.
That said, how can you resist the psychological conundrum of knowing that every time you play a record, you are forever damaging it a little bit... That you're forced to destroy what you love. That like life itself, every minute it's turning brings death a step closer. That one day your old records might match your own ears' diminished high frequency response.
OK, let me qualify: Vinyl (when played on commodity equipment) does, almost unavoidably, suffer mild (or worse) analog degradation. This is why (if you're of a certain age) you'll recall that for high-value purchases, we usually made cold replicas (uh, "tapes") to insure that the "master" got played as infrequently as possible.
CDs, however, not only degrade spontaneously (even when stored "properly"), but the degradation is pretty much "either-or" -- when they do degrade, usually the whole thing is pretty much unplayable (unless you're putting it in a very expensive player).
In any case, from my own extensive experience over the years, item for item, I've had quite a few vinyl records suffer "moderate" deterioration (aftr heavy playing), but virtually all were still playable to some degree. Really - unless you leave them in the back of your car for too long, that's usually the worst that happens.
Meanwhile, an annoyingly high % if CDs simply get scuffed, or are left out in the air too long -- and end up irreparably damaged and unplayable (at least on generic players).
Other than some exceptionally rare examples of "bit rot" where errors in manufacturing cause the chemical composition of the plastics prematurely deteriorate, a compact disc will survive at least 50 if not 100 or more years, even with the most exceptionally modest storage and handling conditions.
A scuffed CD is often perfectly playable, and can otherwise be polished back to near-perfect playability with toothpaste and/or ultra-fine sandpapers.
Funny, I still remember buying my first CD as a kid, Motley Crue's Girls, Girls, Girls (ouch!). The packaging back then was different and they'd put the CDs in long boxes whereas now you just buy it in the jewel case. I remember how cool it was getting a boombox that had a tape deck and a CD player and being able to make better mixtapes.
I remember reading that longboxes were a way to prop up the LP jacket manufacturers, since the materials and process were similar, but... "citation needed".
There were three and a lot of noise around them at the time: HDCD; DVD-A; and SACD. A very small handful of audiophiles cared, nobody else was paying enough attention to hear the difference. (For the people who are going to bring up Nyquist, that is true of the frequency domain, but not of the time domain, and differences in timing affect spatial resolution more audibly than they do timbre.) Really, it only matters to people for whom listening to music is an activity unto itself, and we're a really small group. You can still get good players, but the catalog of available media is a few Sony-owned classics in SACD and the odd bit of audiophile porn (you know, where the recording is amazing, but the actual performance wasn't really worth the bother of recording it).
Assuming 44.1kHz sampling rate the smallest path length difference between the ears is approximately 6.8mm. This corresponds to 2.3 degrees (with sounds source at infinity). Humans can place sounds with about 3 degrees of resolution so unless you have some citations I am seriously skeptical about the claim that higher sampling frequencies gives you anything whatsoever.
44.1KHz is not the output frequency; it's the sampling frequency from which an unambiguous 20KHz signal (of sufficient amplitude) can be reconstructed. So your calculation needs to take into account that the maximum peak resolution is 20Khz (and that 16 bits may not have sufficient amplitude sampling resolution to accurately interpolate the waveform peaks even if their frequency -- their spacing rather than their position in time -- can be reconstructed unambiguously).
Completely agreed about 44.1kHz being a sampling rate. To make the rest of the numbers nicer I'm going to pretend we're talking about 40kHz sampling for the rest of this comment. It's clear that you can't distinguish between a 0-degree phase shifted 20kHz signal and a 0-degree phase shifted 60.0kHz signal (I thought we weren't going to talk about Nyquist here). However by the same token you CAN represent a 90-degree phase shifted 20kHz just fine. By way of example consider the bit stream (I'm also pretending 1-bit sampling for now) [0 1 0 1 0 1] which in this format represents a 20kHz signal. It's pretty obvious that we can represent the 90-degree phase shifted signal as [1 0 1 0 1 0] and there's nothing in the input stage that stops the original source from creating this particular type of signal. In fact we can unambiguously represent ANY phase shift in the same fashion, but as you point out then we start arguing about whether your sample has enough precision to unambiguously represent the input. With a 90-degree shift (corresponding to a ~23usec delay) we have none of the precision problems you allude to.
But then you have to ask what actually matters, if the final delivery destination of this information is the ear canal of an adult human.
Given the speed of sound through air, how does a ~23usec time offset compare to the involuntary micro-movements of the head of a typical conscious human?
Never. First, CD audio quality is good enough. Second, the market is in transition (already transitioned?) to a pure digital format, distributed either via flat files (e.g. mp3s), or via SaaS streaming services.
Similarly, Blu-ray is probably the last physical format for movies.
Well there is still an option for so called high definition digital downloads. Although MP3 audio quality is good enough, I wouldn't rule out the possibility of companies marketing "high frequency" "lossless" recordings at a premium price.
NPR mentioned this morning that digital music download sales far exceed physical media music sales already. This might explain there being virtually no record stores around anymore.
It's not 'far exceed' - last year was the first that digital sales exceeded CD sales, by something less than a percentage point. Still, it's nothing to sneeze at.
TFA from this past submission was the thing that finally persuaded me to believe that CD quality audio is all you need for optimal stereophonic listening.
The primarily advantage of SACD is that the recording has probably been remastered at the proper loudness to suit the tastes of SACD's audience--not for uniformly high levels of noise pollution on FM radio and its ilk.
This article also reminds me of where I used to pick up CD's back when they first came out - Tower Records in Mountain View, CA. CD's - still around; Tower Records - not so much. Interesting how it all worked out.
The reason we loved Tower is the reason it died: just about every one of its stores was a record museum. You could find almost anything you were looking for, which meant that they had to stock just about everything anyone would ever be looking for. If I'd damaged (or inadvertently "lent" permanently) an album that was a somewhat obscure gem in a less-than-popular genre when I'd bought it ten years previous, I could always walk into Tower and get a new copy. Great for the customer, but I can't see it being a great business model overall.
So I dropped out of college for a few years, and during that period I worked at the Tower Records in Atlanta for about 2 years. This was First Gulf War time, so it must have been 90-91. Fun job, still friends with more people from that job than any other I've had. It was no one's first record store job, so everyone there was pretty knowledgeable about at least a couple musical genres. Company was not exactly a model of good management techniques, but whatever, as a sales clerk it was great fun.
Anyway, I remember one night stuck on the cash register and bored, so I did some literal back of the envelope calculations. I took the CD storage capacity and the trend in increasing data rates for modems and figured out you'd be able to download albums in a practical amount of time in about the year 2000. I then told all my co-workers to not make a career of the record store business because we were all doomed by digital downloads in about 10 years.
Funny how much I got wrong but still got the end result right.
Three years late to the party (because I couldn't afford a CD player) one customer instead of defaulting on a payment offered me his CD player instead. It came with this CD:
The compact disc has always felt to me to be a decade ahead of its time. In 30 years of removable storage media, we've only managed to go from CD's 700MB to BDXL's 128GB. That's only 182 times the capacity, or 2^7.5
No way! The CD is almost everything you could have asked for in a pre-1995 physical distribution medium. Better-than-your-ear sound quality, cheap to manufacture, no moving parts, relatively robust, allowed for very simple playback hardware designs...
MiniDisc had audibly imperfect sound quality. The media has a complex diskette design with moving parts, is less robust, and requires more complex playback hardware. It was a backwards step in every respect except size and writability.
The perfect product given the technology of the time would have been to just squeeze the regular CD format with all 700MB of data into the 8cm "CD3" form factor. Perhaps adding a "long play" mode suitable for audiobooks (e.g. mono 12 bit/32 kHz PCM).
The minidisc was a great technology at the time, but it's probably for the best that it didn't catch on. Minidiscs used lossy encoding, so ripping your MDs to MP3s would sound pretty bad. And these days, hard drives or flash storage is far superior. What would have been nice is if DVDs and Blu-Ray adopted the MiniDisc form factor... Scratch-free movies from Netflix, in a tiny package that's far quicker and easier to handle.
