Super Audio CDs Rolling Your Way

donutello writes "Slate is running an article about the Rolling Stones Remastered series discs having two layers: CD and SACD. The article contains some interesting information about how Sony is sneakily distributing SACD players without the buyers noticing it. This FAQ provides some information about SACDs. Don't expect to be able to play or reproduce these on your computer anytime soon. The SACD format contains a physical watermark on the disc. SACD players will only play discs with valid watermarks. Music watermarks had two opponents: The audiophiles who didn't like their music distorted and people who didn't like the watermarks preventing copying of the music. With the physical watermarks, they have found a way to appease the former while still stopping the latter thus causing a break in the ranks of the opposition."

Comments

Re:Independent recording?

[tato (and tato only)]

If this law is passed, it will be a felony even to try to produce works in this format without a license, and there will be no obligation for a license to be made available to your small label at any price. Small labels and independent artists lose.

Keep your unimpaired CD players, people.

There is a diagram of

[eclectro]

how it works here

Re:What kind of CD

[Jeremy Erwin]

1. SACDs don't store data using 96KHz/24bit PCM. They use 2.82/1 bit Direct Stream Digital. (PCM records a 24 bit volume sample, 96000 times a second. A Direct Stream Digital recording simply indicates whether the sound should be louder or softer than before. DSD is also (generically) known as pulse width modulation.

Think of sending directions to a plotting device. One method (PCM) should say (0,0),(pi/2, 1), (pi, 0), (3pi/2, -1), (2pi, 0). The DSD way says up,down,down,up ...

There are a number of supposed benefits to recording using Direct Stream Digital, but it's difficult to edit without converting first to PCM.
Many DVD-Audio players limit the resolution of the S/PDIF output to 48 KHz.

The Sharp DX -SX1 SACD player has digital output (admttedly its proprietary, but so what? Most DACS can't decode PWM)...

Re:SACD, mp3, and more

[HowIsMyDriving?]

I have an SACD player and I can play all the burned CD copies that I want. The only thing that you can't do rip the 4.7g data stream. You CAN RIP A SACD HYBRID DISK TO MP3. It will play in any regular cd player. This includes cd drives.

Re:SACD, mp3, and more

[FatRatBastard]

Its not bending the consumer over because its DUAL LAYERED. i.e. an average everyday CD player sees it as an average everyday CD. Rip away!

What you can't rip is the enhanced audio stream (on the DVD layer), but as someone else pointed out earlier you really wouldn't want to anyway if all you're doing is compressing down to mp3.

Vinyl "Fidelity"

[sunspot42]

>Everyone with any knowledge of audio will agree that CDs are
>a poor format. Crappy error-correction, only 16-bit precision
>(20 is optimal), and a relatively low sampling rate are all
>problems. Guess why audiophiles mostly listen to vinyl.

Amazing how much you can get wrong in three little sentences. CDs are a fantastic audio delivery format when compared to their predecessors. CD error protection is fairly bulletproof - witness the ability of most quality (and many cheap) players to track even severely scratched discs, while inaudibly correcting for any read errors the optics can't get past. Try doing that with a scratched analog LP or jammed tape. CD's 44.1 kHz sampling rate meanwhile is adequate to reproduce the full 20 Hz - 20 kHz range of human hearing, and then some (this article explains how the oddball 44.1 kHz became the standard).

As for "audiophiles", I don't know how you'd possibly go about defining an audiophile these days, now that many low end consumer multichannel receivers and surround speaker systems boast specs that demolish those possessed by high-end, $1000+ pieces of equipment just a decade ago. I do know there are plenty of self-identified audiophiles out there who won't touch vinyl with a 10 foot pole. Given the format's numerous limitations, I can't say I blame them:

* Loud tics and pops caused by stray dust and wear, resulting in a *negative* signal to noise ratio - i.e. the noise can become louder than the music! (with N'Stynk, I suppose this would be a blessing in disguise . . . or simply redundant.)
* Rumbling caused by the turntable's motor and the friction of the stylus as it passes through the groove
* Wow and flutter, caused by speed irregularities in the turntable's drive system and by any imperfections in the geometry of the disc
* Phase irregularities caused by the RIAA equalization and the subsequent need for the preamp to de-equalize the signal
* Frequency response irregularities caused by the RIAA equalization / de-equalization process
* The inability to reproduce loud bass accurately (the cutter making the wax master would pop out of its groove if it tried to reproduce the kind of bass CDs can handle effortlessly)
* The tendency for the turntable, platter and even the disc to function as microphones, picking up room reverberations and - particularly - the sound being produced by the speakers, smearing and distorting the audio in numerous ways
* Cartridge / tonearm misalignments, causing inaccurate stylus pickup, accelerated record wear, or both.
30dB of stereo separation, vs. CD's 70+dB of separation
* A theoretical maximum of 60dB of dynamic range for virgin vinyl of the highest quality (and only at certain frequencies - obviously, not in the low bass) vs. around 90dB of dynamic range from even the cheapest CD players, across the entire spectrum
* In practice, roughly 40dB of usable dynamic range across the majority of the spectrum
* A relatively flat frequency response from only around 60 Hz to 15 kHz, with severe rolloffs beyond those limits
* The need for mastering engineers to severely compress and re-equalize the signal in order to steer clear of the format's limitations relative to CD, which requires no such distortion-educing compensation
* Pitch and frequency errors caused by the speed difference between the cutter used to produce the wax master and your turntable
* The tendency of the media itself to wear out as its played, and to be damaged during routine handling with audible results

CDs are based on 25 year old technology now. Newer formats - such as DVD Audio - offer even more impressive specifications (and multichannel audio capabilities), but the difference between them and the Compact Disc is nothing like the quantum leap in fidelity the CD represents vs. the vinyl LP. Vinyl was obsolete for at least a decade before the CD rolled along, and it was probably only confusion in the marketplace regarding the various tape formats (the 8-track, Philips' compact cassette, open reel) that allowed it to survive as long as it did.

Re:Vinyl "Fidelity"

[sunspot42]

>The timbre of the musical instruments in vinyl is subjectively superior (to my ears and many other peoples) to that of CDs.

Yes, I have no doubt it is - for reasons I cited in my posts. This has nothing to do with the fidelity offered by the vinyl LP format however, which is absolute rubbish compared to the Compact Disc's. The LP is 1940's technology, so this is hardly surprising.

>This is due to digital nature of CDs. The waveform produced from a CD
>is interpolated from data per unit of time. This is not as precise as the
>waveform produced from a vinyl record which doesn't require D/A interpolation.

What you've just said makes absolutely no sense. CDs record samples of sound over 44 thousand times *per-second*. The human ear has no way to discern the difference between audio sampled at such a high rate and a "continuous" analog waveform. Numerous A/B tests have been conducted, and participants have been consistently shown to be unable to tell the difference between an analog master tape and a well-made digital copy. Many of the earliest A/D and D/A converters were plagued with conversion issues and other performance limitations twenty years ago, but those have all been resolved now for well over a decade.

Arguing that the resulting analog waveform produced by a CD player's D/A converters is not as "precise" as the analog waveform produced from a vinyl record is laughable. The signal being recorded on the vinyl has already been subjected to processing not required for transcription onto CD, including at least two equalization passes (one to compensate for vinyl's physical limitations regarding low bass and other frequency response issues, and another to make it conform to the standardized RIAA equalization curve) and dynamic range compression (in order to compensate for vinyl's limited dynamic range relative to the studio master tapes and CD, not to mention all the noise discs typically accumulate as they're used, plus the noise generated by the turntable and stylus). The equalization and compression alone cause all sorts of phase issues, plus harmonic distortion, and they compromise the flatness of the overall frequency response. On top of that, throw in the physical imperfection of the disc itself, wow and flutter and speed irregularities both for the cutter and for your turntable, plus turntable, platter and disc resonance effects and any electrical hum being picked up by your cartridge and phono preamp . . . well, it's plain to see the waveform coming off even the best turntable is going to be a heck of a lot less precise than the waveform coming off a well-made CD. You may prefer the sound of the LP for whatever reason, but there's no way on earth you can back up the assertion that it's more "precise".

>Also, while the ear hears pitch from roughly 20Hz to 20kHz, the ear perceives
>sound of much higher frequencies, not as pitch, but as directional encoding.

Again, this simply isn't true. Young children can hear out to 20kHz, and occasionally even beyond (I think the observed limit is around 22-24kHz - CDs top out at a theoretical maximum of 22kHz, but due to the nature of PCM encoding at 44.1kHz, filters have to be put into place to limit high-frequency sound much beyond 20kHz), but it's vital to note that even then, the sensitivity of our ears to sound at 20kHz is extraordinarily low. In other words, a sound at 20kHz would have to be phenomenally loud for us to hear it compared to a sound at, say, 5,000Hz, where our hearing is much, much more sensitive. Few musical instruments produce loud sounds at or above 20kHz as a result - at least, not intentionally. There could be harmonics at frequencies in excess of 20kHz (for example, perhaps cymbals produce such harmonics), but by their very nature, those harmonics are going to be soft in relation to the rest of the signal - and again, most adults don't stand a snowball's chance of hearing them anyhow, even if they were deafeningly loud, which they're not.

Worse, vinyl doesn't stand a snowball's chance of reproducing such ultrasonic information with any kind of accuracy. The format was never designed to record high frequency signals - engineers have enough trouble squeezing 60Hz - 15,000Hz out of them reliably, let alone with any kind of fidelity when compared to CDs. I have no doubt that LPs produce a fair amount of ultrasonic signal, but again, most of that is going to be unintentional - clicks and pops, surface noise, electrical noise, and harmonic distortion generated by the stylus and cartridge as they vibrate. Any "real" ultrasonic information on the record would be swamped by all the fake ultrasonic garbage. You also seem to be assuming that the master tapes contain such ultrasonic information. They don't. The usable frequency response of even the best analog tape decks used historically for studio recording typically topped out at around 25kHz. Beyond that the levels fall off so rapidly as to be useless, and even there, the levels are going to be pretty low (assuming the deck doesn't employ filtering beyond around 22kHz to eliminate unwanted ultrasonic noise that can impinge on the bias signal).

Of course, this assumes the microphones could even pick up such ultrasonics to begin with, which of course they can't. 99.9% of the microphones used over the past 60 years to record audio in the studio or concert hall are lucky to have a usable frequency response out to as far as 20kHz - most begin a pretty severe rolloff at 15kHz, and by 20kHz only a handful manage to maintain a flat response, with performance dropping off rapidly thereafter. Anything they're picking up beyond 20kHz is going to be so faint as to be inaudible once it passes through the gauntlet of noise and distortion inherent in the vinyl format. Here's a sales listing for the legendary Neumann U87, a mic that's been the studio standard for vocal recording since the '60s - the Beatles used this mic, and singers & engineers continue to choose this mic over all others even to this day. Its frequency response tops out at 20kHz. So much for recording ultrasonics. And the instrument probably most likely to produce ultrasonics - the cymbal - is typically recorded using a mic like the Shure SM57, which has been a standard for recording percussion since its introduction over thirty years ago. Its frequency response tops out at a measly 15kHz. What ultrasonics?

Of course, it's all utterly inconsequential compared to the trashing of the original waveform caused by all of vinyl's other numerous limitations, including the damage done in the crucial 50Hz-5,000Hz range where human hearing and perception is so much more sensitive, and accuracy therefore so much more important.

>In summation, the superior S/N ratio, channel separation, and decreased
>vulnerablity to reproduction errors of CD's are not as important as the
>superior timbre and staging provided by vinyl.

In summation, you're clearly uninformed from a technical standpoint. If you prefer the "sound" of vinyl, that's your business. But don't try to cloak your preference in technobabble you clearly don't begin to understand.

It's not secret and they run Linux fine

[blp]

I have a brand new IBM ThinkPad T30 with a TCPA chip, and I have been running Debian GNU/Linux on it from day one. In fact, the Microsoft OS it came with has never been booted. If I could just get ATI to give me specs on the video card, so that I could make suspend/resume work better, I'd be entirely satisfied with it.

Now, this is not to say that TCPA does not have some unsettling implications. For now, TCPA-enabled machines can boot "trusted" or "untrusted" OSes. What worries me is what might happens years in the future, when TCPA or its moral equivalent is in just about every machine and "trusted" OSes are the exception, not the rule, on mainstream users' PCs (should that ever come to pass). At that point, I'll start getting worried about the possibility that manufacturers might turn off the ability to boot an untrusted OS.