The Compact Disc: An Introduction

The Compact Disc: An Introduction

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Lasers! Rainbows! The eighties! Drum Machines! Digital! Big hair! This is some righteous stuff! No kidding, the compact disc was a radical
departure from how, well really how a lot of stuff worked. You could argue that the CD, with its vast
data capacity, relatively robust nature, and with the further developments it spurred along,
changed how the world did virtually all media. That is at least until physical media became
the seemingly undesirable thing it is today, a time when streaming services and libraries
on hard drives are all the rage. Unless of course it’s vinyl, then by all
means please build your collections. Wow the snark’s coming early today. Well, this is the third video in a series
on digital sound. You can find a playlist to the previous two
videos, in which we covered how digital sound works (as well as the Nyquist-Shannon sampling
theorem), but for now, sit back and relax as you feast your eyes on the silver platter
that is the compact disc. No discussion of the Compact Disc is a good
discussion unless it pays homage to its predecessor, the LaserDisc. Now, I’ve done a series on Laserdisc if
you’d like to learn more, but in brief, this was the very first commercial optical
storage format. First released in test markets in 1978, Laserdiscs
were usually 12 inch or 30 centimeter discs, and they were an analog video format, holding
up to one hour of video per side. Competing in a world where the videocassette
recorder which could record from live TV already existed, the Laserdisc failed to capture the
hearts and minds of many individuals even though it had steller video quality. Throughout its life, it stayed a videophile-only
format in most markets. But, the development of the Laserdisc, which
was done in large part by Philips, presented an obvious solution to the problem of digital
sound storage. See, although Laserdisc is an analog format,
the signals encoded on it are as a series of pits and lands. OK, optical disc fundamentals time! You might already be aware of this, but optical
discs are read by shining a laser up at a reflective disc that is covered with little
pits. These pits are roughly one quarter as deep
as the wavelength of laser light that will hit them. I ran into some inconsistencies regarding
the exact depth of the pits, because the only source I found which specifies it has the
wrong wavelength of light listed for the CD, but all you need to know is that when the
focused laser hits a pit, the increased depth causes the reflected light to destructively
interfere with the projected light, which reduces the overall intensity of the light
reflected back. That’s actually a pretty neat part that often
gets overlooked. Endless articles talk about the fact that
the pits change how the light is reflected, but very few mention the destructive interference
aspect of it. I’ve shown this diagram before, and it perfectly
demonstrates what happens. When the laser hits a not-pit, the light gets
reflected right back down to the laser, and a prism reflects some of this into the photocell. But when it hits a pit, the destructive interference
greatly reduces the intensity of the reflected light, so very little light hits the photocell. This is how a laser pickup system can tell
the difference between a pit and a land. In the LaserDisc system, these pits and lands
were used to encode analog video and audio signals via a weird hybrid of pulse-width
modulation and frequency modulation– Don’t ask, it’s complicated –and the result is
a usable analog video signal from a shiny plastic disc. So, having already invented a thing that used
lasers to read information on a disc, when it came time for a digital music format to
hit the scene, Philips was poised to knock it out of the park with a new disc, this one
no less lasery, but quite a bit more compact. They named the format along the lines of their
previous compact invention, the compact cassette, and in a non-coincidence, the diameter of
the CD is roughly the same as the diagonal length of the Compact Cassette. Ah, but let’s not forget Sony’s role. Sony, the people who seem to only make either
runaway successes or disastrous failures, had been working on digital audio for some
time. They were the ones that developed a PCM adapter
for use with U-Matic videocassette recorders as discussed in the previous video, and in
fact they were working on an digital optical audio disc before Philips released the Laserdisc. One of their early prototypes from 1977 was
the same size as one of these honkers and held only an hour of digital audio, though
at the same exact quality of the soon-to-be Compact Disc-Digital Audio standard. Philips and Sony were sort of working on the
same thing at the same time, though Philips had the notable advantage of having already
developed and manufactured the Laserdisc by the time things really heated up. Still, Sony contributed a lot. I don’t want to get too into the weeds of
who did what, so let’s just jump to 1979, the year that Sony and Philips first decided
to for realsies collaborate on the project. By this time, optical disc fundamentals had
been established. An optical disc seemed the perfect format
for digital data, because you could just easily call a pit a one and a land a zero. But that’s not how it works! No, the pits and lands are important, but
it is the change between a pit and a land that encodes a 1, and no change encodes a
zero. This is time-based, so a four-bit span of
time which is comprised of either all pits or all lands will produce 4 zero bits. Start the sequence with a change and then
continue as is, and you get 1000. No change, change, no change, no change, and
you get 0100. And you get the idea. This is called Non-Return-To-Zero inverted
encoding. Now, this has limitations because a long span
of zeros requires an outside clock to keep track of how many “dead” spaces have passed. The longer you have between ones, or changes,
the more ambiguous the number of zeroes becomes. I know what you’re thinking. Was that six zeros or only five? Well, to tell you the truth in all this excitement
I kinda lost track myself. Which is why you need an outside timing source
keeping track of how many shots, I mean bits, have passed. This isn’t somewhere you should just feel
lucky. But that’s not a problem. What is a problem is the nature of everything. How likely do you think it is that a pressed
CD is absolutely perfect, has no scratches at all, and that the CD player reading the
disc will perfectly, without any errors, reproduce the correct sequence of ones and zeros? If you answered “not likely at all” you’re
a winner! To help make the data less susceptible to
stupid little things, two robust error-fighting mechanisms are built into the data stream. The Red-Book standard, the first of the Rainbow
Books that defines the physical, digital, and other various standards surrounding each
type of Compact Disc, not only specifies the sample rate and bit depth of the Compact Disc
Digital Audio format, which as previously discussed is 44.1 kilohertz, 16 bit, but it
also defines how the data is encoded on the disc. Now this is rather technical but I think interesting,
so bear with me. So, each audio sample is a signed, which means
it can be positive or negative, 16 bit two’s complement, which is a mathematical operation on binary numbers that we’re just gonna not worry about right now because it hurts my brain, integer. I mean, we knew we’re dealing with 16 bit
audio so each sample is gonna be 16 bits. Now, on the disc, 12 samples, 6 each for the
left and right channels, are stored together in a frame of 192 bits (that’s 24 bytes,
for those playing along at home). These frames are then encoded using an error
correction scheme called CIRC, which stands for Cross-interleaved Reed-Solomon coding. In addition to adding one data parity byte
to every three raw data bytes, the effect of CIRC is basically to spread the data out
over a longer distance. That’s where the interleaving part of the
name comes from. By jumbling up multiple frames and adding
parity bytes, CIRC can correct up to 3,500 bits of error-filled or even missing data,
and can compensate for up to 12,000 bits by masking errors via interpolation. This translates to up to 2.4mm gaps in data
being completely corrected for, and up to an 8.5mm scrambling of data, either through
a scratch or some other damage, being reasonably interpolated and masked. The end result is that the error is either
completely corrected, or it’s fudged well enough that you won’t hear it. Now we’re gonna go on a minor tangent here. I apologize. I’ve linked in the description the source
material from the Wikipedia article on CIRC. This source material is from a book written
by Kees Schouhamer Immink, one of the central engineers involved in the development of the
Compact Disc. He even won an Emmy for his work on coding
technology for optical recording formats. I’m bringing this up because for every person
that tells you Wikipedia is a worthless starting point for research, I want you to show them
the references section at the bottom of articles. Yes, you would be very unwise to cite “Wikipedia”
in any research, but let me tell you, you may be amazed at the quality of the source
material, and you’d be a fool to not at least look at these references when doing
any preliminary research of your own. Rant over. In addition to CIRC, the use of eight-to-fourteen
modulation limits the total number of possible combinations of ones and zeros. EFM translates each 8 bit word into a 14 bit
word. These 14 bit words are translated back into
their original 8 bit words using a lookup table. The point of doing this is to reduce the possibility
of errors. The use of EFM makes it such that binary ones
are always separated by at least two zeros, and a maximum of 10 zeros. This means that every pit and land is at least
3 clock cycles long. It also means that if the CD player reads
one, zero, one, it knows it must have made an error because that’s not a possible sequence. Plus, with a maximum of 10 zeroes, it reduces
the accuracy required in the clock of the CD player for worst-case clock recovery, as
there must be a one after every eleventh bit, and this will in effect synchronize and restart
the zero-counting clock. Keep in mind that with simple 8 bit encoding,
in theory you could have 14 zeros in a row. When you realize all of the processing that
has to be done by the CD player before it can even extract the data it needs to send
to the DAC and play the dang music, you gain a newfound respect for its achievements of
the time. Granted, using a look-up table and performing
some basic arithmetic is easy for a computer, but the fact that this was being done at a
consumer hardware level in 1982, with a data throughput faster than what any contemporary
microcomputer would reasonably be expected to process, impresses me. To help provide logical access to the contents
of the disc, the disc’s data stream is divided into three parts. The lead-in, the program area, and lead-out. The lead-in contains the disc’s Table of
Contents, which is basically an announcement to the player of how long it is, how many
tracks it contains, and what the timecode is for each of the tracks. The CD player can, through reading the table
of contents, determine where each track is for accessing it nearly instantly. A CD can have up to 99 tracks, which themselves
can be divided further into 100 indexes, though this feature was rarely ever used and few
CD players could access the index information. One thing that computers have made a little
confusing about the Compact Disc-Digital Audio standard is that audio CDs do not contain
files. If you pop one into a PC, it’s gonna show
you each track as its own object. But the computer is interpreting that for
you. In raw form, the data on a CD is just one
continuous stream, and the table-of-contents in the lead-in simply defines where along
the stream each track is. The concept of using a CD for computer data
storage just wasn’t really in the cards yet. I mean, a single audio track would easily
fill up entire hard drives of the time, so the idea of creating files to contain the
audio data was just absurd. The later CD-ROM, following the Yellow-book
standard, would allow for file structures on discs like a computer is used to accessing. But we’ll get to that later. OK, so let’s look a little bit closer at
the disc itself. First, I want you to see if you can spot a
big difference between a Laserdisc and a CD. Looking at the edge of a Laserdisc, can you
see that seam in the middle? Laserdiscs are obviously double sided, so
that seam is the join between the two halves of the disc, and the data is sandwiched between
two sides. But if you look at the CD, there is no seam. One of the weirder things about the CD is
that the data layer is actually at the top of the disc, just beneath the label. I’ve linked to a How It’s Made episode
on the Compact Disc that does a pretty good job of demonstrating how mass-produced discs
are made. Their manufacture is surprisingly similar
to that of conventional vinyl records, as they are stamped (or rather molded) from a
master disc. The video does a great job of showing this
process, but it skips over the actual etching of the data onto the glass master. In short, the master is covered in a solution
that will either evaporate or harden when exposed to laser light, depending on the mastering
process used. By using the laser to etch pits into the coating,
which is then hardened with a development process, the glass master is now covered in
bumps that will represent the lands in the molded discs. The master disc is metallized to harden these
bumps, and now polycarbonate discs are molded from it. And that’s something that I find really
neat about the Compact Disc. The data in stamped discs is actually in the
plastic itself. When the disc comes out of the mold, it’s
completely transparent. But it has all of the data on its surface. To make the disc readable, it’s then covered
in a thin film of aluminum via a vapor metallization process, and now the disc could theoretically
be read by a CD player. But remember, those pits and lands are on
the top of the disc, exposed. If they could be touched, the data would be
destroyed. So before the disc can be handled, it needs
a thin coat of varnish to be spread along the top, and now the data is protected from
damage. Putting the data layer on the top of the disc
meant that the disc was even more tolerant of scratches, as these scratches are out of
focus to the laser reading the disc from below. This was a pretty smart move. The laser would read through almost the entire
1.2mm thickness of the CD. As a consequence, double-sided CDs were never
a legitimate thing. But there were some weird shenanigans tried
with making double sided hybrid discs. One of these I have somewhere in my collection
but I couldn’t find it because I’m disorganized, (sorry) is the DualDisc. “Weird Al” Yankovic’s twelfth studio
album, Straight Outta Lynwood, was released in 2006 as a DualDisc, with one side being
a fully compliant DVD containing music videos and other goodies, and the other side being
a… almost CD. DualDiscs were .3mm thicker than a standard
CD or DVD, comprising a total thickness of 1.5mm rather than the standard 1.2. The CD layer was placed .9 mm into the disc,
with the DVD layer .6 into the disc from the other side, which is correct for a DVD. But it’s off by at least .2mm according
to the Red Book standard. Because of this, DualDiscs did not contain
the Compact Disc Digital Audio logo on them because they technically weren’t CDs. They featured language saying that they were
intended to work in standard CD players, and almost certainly they would given the tolerances
a standard CD player is designed to deal with, but they could not actually be officially
referred to as a Compact Disc. So there’s some fun trivia for you. AAAND, that’s where we’ll hit pause. There’s a lot of neat stuff to uncover about
the CD, even though it’s teetering on the edge of obsolete and insignificant. OK, it is pretty much obsolete. This dime-sized SD card holds more data than
this entire column of CDs. That’s kinda sad, but also amazing. In my next video on this subject, we’ll
explore more of the innards of the compact disc, such as the optical pickups mechanisms
and the rather major difference between how Philips designed its laser pickup compared
to most others. If you take a look at the disc tray on this
Magnavox unit, you might get a hint. Of course we’ll also touch on the other
various uses of the CD, such as CD-ROM, CD-R and CD-RW, and other stuff. And then, we’ll relish in the fact that
everything is on the Internet now. Thanks for watching, I hope you enjoyed the
video! If this is your first time coming across the
channel and you liked what you saw, please consider subscribing! As always, thank you to everyone who supports
this channel on Patreon, especially the fine folks that have been scrolling up your screen. If you’re interested in making a contribution
to the channel to help it grow, please check out my Patreon page. Thanks for your consideration! Don’t forget there’s a Technology Connections
subreddit now, so if you’re a redditer you can go over there and watch me not know how
to use it, and I’m getting better a Twitter so if that’s something you do, you can follow
me @TechConnectify. Anyway, that’s it for now. I’ll see you next time! Cue obnoxious music! ♫ uncomfortably smooth jazz ♫ This line read better before… With its vast data capacity, relatively lobrust… this line. This line is going to kill me! When it came time for digital music formats
to hit the scene, Philips was poised to knock it out of the par–poised? (stares into camera doubting himself) No, that’s what I wrote. That’s what I wrote! I’m regretting it now… The Red Book Standard, the first of the rainbow
books that define the physical, dizhidal, and other… dizhidal dizidal diblelr…. (clears throat) …reduces the accuracy required in the clock
of the CD player for weush… [exasperated sigh] The master disc is metAL…. Metalized.

100 thoughts on “The Compact Disc: An Introduction

  • Brian Cherry Post author

    I learned where the data was stored on a CD in a rough way. I went to a concert by Jason Bonham, and grabbed his latest CD from the merch stand. When I met him after the show he offered to sign my copy. I didn't have a sharpie so he used a ballpoint pen. It scratched off the surface in a few places.

  • PrimiusLovin Post author

    Shout out to everyone who had the experience of interacting with CD technology in the 80's and thinking: what sort of sorcery is this? How does this thing even works? Lands and pits, lasers?!

  • Berk Karşı Post author

    That intro was fire!

  • Franny Dimitri Post author

    lol im using the opening sample in my music … perfect! 😀

  • Roberto XS Post author

    I hate when people shit on Wikipedia. References are everything!

  • PolizeiPaul Post author

    I think Lazer Disc failed cause of it's sheer size and time limit on video, When DVD came out and they learned how much more hours they could hold and the size was smaller, Why didn't the Lazer Disc makers take note and try to replicate things the way a DVD worked, Would have likely saved them.

  • Foebane72 Post author

    I still burn optical media to this day, BECAUSE IT CAN'T BE DELETED.

  • Johnny John Post author

    Whenever you flub a line in your bloopers reel you reach down to your right and do something. What are you doing?

  • MrocznyTechnik Post author

    Do you know any CD player with signal quality indicator? I mean bit error rate indicator of some kind how much data passed OK, how much has been recovered with the help of CRC and how much is lost.

  • KevinMiruku Post author

    tong twister, isn't it? xD Bloopers are fun.

  • Nalsii Post author

    Great video, but why is there a black rectangle over you at 14:32?

  • Ravindra Nagrecha Post author

    For some reason, it is very unlikely for me to understand all the concept mentioned in this video 🙁

  • RegalT-type Post author

    I have that strait outa Lynwood album, I also can’t find it

  • BATTLEWOLF578 GAMING Post author

    The how its made episode has been removed due to copyright

  • Kiddo 9000 Post author

    The how its made episode on compact discs you linked in the video is blocked in Canada. "This video contains content from Discovery International, who has blocked it in your country on copyright grounds" sometimes living in Canada ain't fun.

  • Adolf Göbbels Post author

    Near on no CD these days complies to the Red Book Standard.! They do not contain the Compact Disc Digital Audio logo and the sound and build quality is nowhere near as good.!

  • Trqnssgxvql Post author

    i love audio compact discs

  • Time-Lapser PRO Post author

    Thumbs up for They Might Be Giants!

  • Seventhday Savior Post author

    I have a CD player from 1987. It still works marvelously! If you were around for it and old enough to remember it, I remember CD players being sold for as low as $15/$20 brand new by the time MP3 players had a strong foothold in the early/mid 2000's. I bought my first CD player at Sam's club back in 1997, it was a RCA RP-7932A CD/CASETTE player combo unit. And I saved $60 for it, which with inflation today would be around $100.

  • Scott Lowell Post author

    My first CD player was a mid 80's Akai. It was pathetic for many reasons. The unit itself skipped if you sneezed too hard. It BADLY interfered with radio and TV. The early CD pressings from Japan had a poor use of the RIAA curve. This resulted in tinny and thin recordings. Not to mention, too many were bad transfers with hiss and noise. When the German pressing plant came online, I started getting better recordings. I briefly had a Carver DTL-200 (lemon) which was designed to soft-eq the bad cd's. It was decent sounding (especially with digital time lens activated) but the transport fell apart. My first decent CD player was a sony in 1988.

  • mono man Post author

    at least you can buy film cd.'s dead cheap now 2nd hand…

  • Steve Post author

    Until about probably 1988 or 89, nobody had a "Compact Disc Player" unless they were rich. And yes, it was called by its full name until probably around 1990 or so. The only person I knew who had one was literally a kid who's parents were millionaires. All us po' kids made due with our Walkmans (or in my case, my Panasonic portable cassette player, the extra po' man's Walkman).

  • George Fiddler Post author

    Absolutely Fantastic work!

  • John Aranita Post author

    The Magnavox CD player featured in this video was my first CD player. When I started listening to CDs, the sound felt bumpy. I have well over 100 music CDs, now. I transfer them to my Sony Walkman 16GB. I wish they'd make a Walkman 32GB.

  • StigDesign1 Post author

    women are like Binary they are on or off 😀

  • OtakuUnitedStudio Post author

    Until they start selling albums on SD cards or thumb drives more often, CDs still have a place in the market. Though admittedly I long for the day when music collections cost what they're worth based on number and length of tracks, rather than the fact that they always contain about 80 minutes of music.

    The move to digital distribution is one of those situations where the collector's market is going to shift from contemporary music to vintage. The return of vinyl due to popular demand is a pretty good indication to me at least that physical music media aren't going anywhere just yet.

    So be careful with that O word. My car can still play those things just fine, thank you.

  • GameRetro Post author

    Am I the only one that finds the pronounced CRC as Circ kind of weird? (non native English speaker so forgive me if it's more common than I imagined it to be)

  • MokTheMagicMan1 Post author

    Love the obnoxious music cues

  • Shenaldrac Post author

    When do we get an episode on the Philips CDi?

  • Luke Ranieri Post author

    You make truly wonderful and informative videos! Thank you! Haha 3:40 I can think of another major Sony success and failure: Spider-Man and Pixels 😂

  • audiotron1003 Post author

    With my plus 540 playable CDs of old school electro and hip hop I'm in no hurry to let my so-called obsolete CDs go just yet. Not my 250 taps with even rarer music go either.

  • Stjernefodt Post author

    I had never noticed that DualDiscs don't contain the Compact Disc logo. I have a copy of Judas Priest's Angel of Retribution which was released as a DualDisc, so I immediately pulled it out and, sure enough, there is no Compact Disc logo, though there is the DVD logo. There is even an asterisk next to every usage of the term CD which then has the notation of "The audio side of this disc does not conform to CD specifications and therefore not all DVD and CD players will play the audio side of this disc."

  • Nyrei Post author

    :cd:

  • GIANT DAD THE LEGEND Post author

    Be trasparent. ForsenCD

  • Yale University Admissions Post author

    D OMEGALUL C

  • orcunbab Post author

    forsenCD

  • hytlerson Post author

    two's complement is just invert all bits and add 1 to the inverted number. but you don't see it explained this simply anywhere, the elitist technologists use obfuscating terminology and explanations to make it seem difficult, hard, confusing, inaccessible and only for "very smart" people… Actually, it takes a genius to put/explain things simply (they aren't and resort to obfuscations…).

  • SmithCommaBenjamin Post author

    I used to buy duel disc DVDs. A movie on one side, the sequel on the other.

  • Some Guy Post author

    Please do a video about CD+G. I would like to see your take on this fun format that didn't catch on. I loved enjoying (almost) secret features that most people didn't see. They were playable with regular CD players but without the Graphics, which should have helped the format survive.

  • Fred Zlotnick Post author

    Have you tried looking at the Philips-Sony Yellow-book for CD information?

  • Israel andersonHOME Post author

    I wanna be completely transparent with you guys

  • SapphireFlame Post author

    You say physical media is "seemingly undesirable" which is a sentiment that appears to have been muted by Wii Shop's closure.

  • D I Post author

    Do a video on Sony's Mini Disks players. I thought it was going to take over Compact Discs. Great videos man.

  • arian Kazemzadeh Post author

    neat

  • Returning Shadow Post author

    Your videos are nice and informative but you need to learn the concept that too MUCH information is just as bad as too LITTLE. You need to simply get to the point of your topic WITHOUT give a lifelong history into that topic. Just start giving new info when the topic was introduced. We get it. Laser Disc if the daddy to CDs. That's all you need to say. And you certainly don't need to repeat yourself repeating what you've said in multiple other videos. Just put a link in description and tell people who want to learn the in depth history to go to those videos.

  • Benjamin Otto Post author

    The Compact Disc, truly a technological marvel. And a visionary format.

  • Ritchie Navarro Post author

    I have 500 music cds that i have purchased between 2000 to december 2010.

  • N Hietala Post author

    What's up with the rectangle at 14:32?

  • enrique soza Post author

    These series of CDs videos are amazing. The whole channel is fantastic, everything well explained with simple terms. I would love to learn about MiniDiscs, Dat, and DCC. Please!!! Make us a video of those

  • Matthew Ramada Post author

    "But that isn't a problem; what is a problem is the nature of… everything."

  • supercrapnstuff11 Post author

    Stupid question, is there a red colored book that lead to the name "redbook"
    are they just digital documents or are they some printed internal document?

  • klugshicer Post author

    14:36 Another fun fact: Most CDs today containing audio can't be sold as "compact disc digital audio" either because due to their copyright protection mechanisms don't meet Red-Book standards anymore.

  • Martin Houlton Post author

    Hahaha I love the Dirty Harry reference

  • Pete Post author

    "Down to the Moon" is a great CD!

  • A Human From Earth Post author

    Great Dirty Harry quote – that made my day.

  • robert landoni jr Post author

    3:44 , yes i love Sony stuff, but when ever they make a marketing mistake, boy, do they ever !

  • Val Post author

    2's complement is easy, a negative number is just the bitwise inverse of a number, plus 1, because in 1's complement (where negative numbers are just all the 1's swapped for 0's and vice versa) had an issue where 5 -7 was equal to negative 1, and there were two zeros, a positive and a negative one. :p

    It's also good that any combinational logic can be replaced with a ROM (and vice versa) to do the kind of serious LUT computation 8->14 modulation, etc. requires.

  • themobile player Post author

    37 meters

  • Hrnek Bezucha Post author

    I've got several double discs. They were sometimes bundled with gaming magazines in the distant past.

  • User Uncertain Post author

    “What is a problem is the nature of everything.”

    Because, occasionally, talking about technology makes one sound like a philosopher.

  • Andrei2000PC Post author

    You make me a more gadget geek than ever before.

  • Andrei2000PC Post author

    I love your out takes. Keep them up!

  • Endezeichen Grimm Post author

    Holy fuck! CD's are way more complex than I even thought they were.

  • Dylan Morrison Post author

    I'm so glad two's complement hurts your head because it sure as hell hurts mine as a programmer.

  • Henrik Jørgensen Post author

    I swear, if How It's Made start linking to Technology Connections then I'll be stuck in an infinite loop.

  • Luke Corwin Post author

    We have the Straight Outta' Lynwood dual disc, and I can confirm that both sides work in every player in which we have tried it. After seeing this video, I placed it next to standard CDs and DVDs, and it is noticeably thicker.

  • Mark Grinshpun Post author

    KoRn's "life is Peachy" (1996) album was double disc formatted, one side music, one side live concert music video. KoRn has said that they hated that decision in hindsight bc it destroyed the sound quality of the album. The peachy album was their second album and it sounded much thinner and compressed compared to their 1st album. It could've been a nice bs excuse to not pissoff the producer, mixer and sound engineer…or it could be true IDK, what's your thoughts?

  • MrWillgum Post author

    everytime I hear the dirty harry reference I think of ryan styles doing that scene as carol channing on who's line

  • Spencer Martin Post author

    Ben Eater has an amazing video on Twos complement

    https://www.youtube.com/watch?v=4qH4unVtJkE

    I would suggest anyone watching this to watch that video if you want to further your knowledge.

  • Slipknot3eb Post author

    I like your channel especially your content but usually I don't finish these lenghty videos maybe because I'm used to short informative ones. Btw it's great and full of detail!

  • Joe Rico Post author

    All these years and I’ve NEVER placed a cassette on top of a CD. On my to do list for this weekend.

  • Joe Rico Post author

    All these years and I’ve NEVER placed a cassette on top of a CD. On my to do list for this weekend.

  • slothfulcobra Post author

    I wish SD cards got picked up as the way to physically sell movies, music, or other data, instead of all media getting locked up on sorta-obsolete disks and proprietary streaming services. Perhaps the Nintendo Switch and DS were the real future all along.

  • Nothing Post author

    You know, people harp on corporations a lot, but this video makes me realize we just wouldn't have the technology we have today without corporations running huge R&D, and engineering departments and paying for the research and manufacture costs, as well as marketing. Sure individuals have invented and marketed things successfully, but never any products nearing the complexity of a VCR, optical media, or integrated circuits. Even just making these things is beyond the means of most people. Nevermind making them well, or on an industrial scale. And that's not even taking the research necessary to actually figure it out in the first place.

  • Matt Cooper Post author

    AC/DC's Back in Black was a Dual Disc – https://www.discogs.com/ACDC-Back-In-Black/release/1357019

  • Joseph Hooper Post author

    All I could hear in my brain during the dual disc bit was Seto Kaiba shouting "DUEL DISK SYSTEM!"

  • Official iGamer Post author

    I actually still have a dual disc, its in rough shape, but its by Switchfoot, the Nothing is sound album

  • ralf 67453 Post author

    i needed to see a cd jewel case,i haven't seen one for a while.

  • Waylen Post author

    I don't know many people that want to mess around with a computer just to listen to their music. And computer makes a very poor home stereo.CD on a hi fi stereo sounds better than any file on a computer.Most MP3 are ripped from a CD.Flash media is temporary storage and unreliable,it will give no warning when it fails,Compact disc will give time for you to transfer the data off of one and onto another.<<<<<O.K.,Compact Disc wins,CD is not obsolete.How much a flash card holds is irrelevant when the media is all about protecting the file.

  • Lance Elliott Post author

    Okay, while everything here is interesting the thing that actually blew my mind was that the data layer is the plastic layer.

    WHAT ON EARTH I'VE BEEN A COMPUTER GEEK MY WHOLE LIFE AND JUST ASSUMED IT WAS THE SHINY ALUMINUM LAYER

  • ODST Republic Post author

    I'll never not buy physical copies, just in case something happens to all my cloud stuff

  • ODST Republic Post author

    Signed 16 bit
    Two's complement
    Integer
    Or in other words S.T.I.
    Board room: isnt that close to S.T.D.
    Pitcher: Well yes but no one is going to compare the two, we should be fine.
    Board room: Then it's a deal, well start using that, starting today
    Me: signed 16bit, two's complement, and integer. The acronym of that looks like S.T.I. for sexually transmitted infection (I prefer it to be called disease but oh well)

  • William Wallace Post author

    OMFG lol the movie reference lololol classy

  • Christopher McCord Post author

    There are some CD's that have "negative information". Hootie and the Blowfish's Fairweather Johnson is one of them. Between tracks 3 and 4 my CD player (pioneer) will countdown backwards from -14 second (other CD players will just stay at 0:00) and be will begin singing a chorus to another song before the next song comes on. You will never find this by searching. You HAVE to listen to song 3 and 4 together to hear it. Can anyone explain this?

  • TheSulross Post author

    Wikipedia can be excellent for technical information but on anything that can get political then it will always get skewed by ideological zealots that will monopolize the effective ability to edit the info

  • thomas k Post author

    Fascinating info coupled with a deadpan delivery and dry wit. Kudos.

  • Emily Banks Post author

    pulsewidth modulation ???? so ur saying cds can make square waves ????

  • Narax Post author

    Hold up. Did you just say "obnoxious music"? I am sorry I don't think we can be friends if you think that is obnoxious.

  • Neil Mansfield Post author

    Compact discs and vinyl are coming back.
    They won’t go out

  • Neil Mansfield Post author

    This is interesting

  • Okaro X Post author

    Typical hard disks of around 1982 were 5-10 MB for those lucky to have one. Most used floppies or even audio cassettes.

  • Eric Gray Post author

    I kind of find it amusing how Sony worked with Philips on this optical technology, and little did they know a few years later they would become enemies thanks to Nintendo regarding a similar thing

  • lemons Post author

    I've always wanted the same Kallax shelf from Ikea you have there for storing my CDs, haha.

  • neko Post author

    Snake! Remember the basics of CIRC!
    Hrrh, colonel, I don't care about CDs.

  • The 8 Track Master Post author

    8 tracks are better than cds

  • Bill Hudgens Post author

    I love your humor! “That's 24 bytes for those playing along at home” – 🙂

  • Ma ON Post author

    8 inch or 37 meter, hey, I'm no fan of metric, but methinks that is wrong.

  • Ma ON Post author

    Imagine how the engineers who developed this technology feel.

  • Paul Mansfield Post author

    I once had a Sony CD which had some weird copy protection system and couldn't read it on my hifi DVD player, ir car CD, but my original Xbox ripped it just fine!

  • HOLGER HANSEN Post author

    Tell about NOS DAC.

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