Given how early this was, all CD players at the time would be high end audio equipment - meaning that they'd have balance controls, as well as equaliser dials, etc. So honestly it would likely have been easier then than a few years later when cheaper CD players that played cds and had either presets instead of a graphic equaliser or no equaliser settings, meaning they'd have no balance control either. It's kind of a product of its time.
If Mat was on TV, the damned producers would ruin everything. Again, I'm left to wonder why the fuck people think being on TV is better. If this channel was only on BBC, I (an American) would be out of luck. TH-cam has more reach, because it has no region. People, stop wishing that TH-camrs were on TV. If they were, they'd just turn into more shit TV.
@@md_vandenberg. Actually television currently has more reach globally than TH-cam for the simple reason more people have access to television worldwide than the internet.
Because if it were on any TV format (with TV producers and the people paying for TV, the advertisers) they would want to skew it to their own benefit, read that as "say what we tell you say not the truth" and then we are back to the same silly Bullshit that's; on the Tele already...Here on youtube he can say what he feels is true with out some one telling him what to say. I have a desk top tied to my 65" television, HD video and adequate sound quality. No need for TV at all.
I remember reading about a USA FM radio station in the 80's that was in a town that had two high schools. Both schools wanted to broadcast their football and basketball games on the same station, but their games happened around the same time. So the station compromised by putting one school's game on the left channel and the other school on the right channel.
Well that's a shitty idea, the crosstalk must have been horrendous. The reason is that FM broadcasts the L+R signal and L-R signal, and L-R is off to the side of the band and more subject to degradation.
When I was a radio DJ in the 80's-90's they used regular phone lines for the feed from the stadium or the gym. Some stations still do that, but many are using the internet now.
The diagram in the Trimicron record jacket misled me at first, until I started thinking a bit more 3-dimensionally about it. Since the stylus rides on the sides of the grooves, and not the top or bottom, it doesn't actually matter if the very top of the groove has a different shape than the audio deeper in the groove (where the stylus actually touches). Since grooves are V-shaped, the deeper into the groove you go, the further away from the next groove you become. The one constant is that the sides of the groove need to be 90 degrees from each other in order to be compatible with normal stereo styli. Because the 90-degree angle has to remain, that means the closer you want to pack the grooves to each other, the shallower they have to become. This would, of course, explain the reduced amplitude (the stylus has less material to ride against) but also means that, since the stylus would be riding "higher" in the groove, the tip of it would actually be what picks up the audio, instead of the sides (since styli are somewhat cone-shaped). This could lead to reduced stereo separation, as Fran Blanche mentioned in another comment here (hi Fran!). The Trimicron system simply seems to have come up with the smallest possible ratio between groove pitch and depth such that there's sufficient amplitude, but also the minimal distance between grooves where the stylus rides. Not a horrible idea, really, though it certainly has its drawbacks.
This Does Not Compute I would imagine that it actually does have an effect. My guess is that it is the cause of the reduced dynamic range and audio levels,as the needle has less room to move.
+This Does Not Compute Now you know something about it! I was thinking about the size and length between a vinyl record and a CD, especially the whole album filled with songs too. I thought that a vinyl record will last 1 hour to make a full album just like the CDs from a long time ago.
This Does Not Compute incredible explanation! I've also experienced this change in a few records I own. I've had a Fleetwood Mac Greatest Hits record for a while now, and I recently found a copy of their album "Rumours." I've noticed quite a difference in amplitude and depth that's obviously due to the amount of surface area that each track takes up. The track I used for reference was "Dreams."
This technique certainly has its drawbacks. Because the recordings are much more quiet, you are much more prone to notice higher levels of surface noise and crackles as a result. Okay for "throw away" compilation albums that are not very important, where a record is expected just a few plays in its lifetime; but something not to be considered for prized and important record releases though. The sound quality degrades at a much faster rate due to stylus playwear and contamination from dust, dirt and mishandling issues.
These aren't media formats, since you can still play on normal CD players and record players. Just mono stacking for the CD, and reduced amplitude and dynamic range to squeeze the grooves closer together for vinyl. K-Tel records did this all the time to pack songs onto vinyl, but the songs sound flat as a result.
Hey ! Is about to buy model Pioneer PD-TM 1,2,3 CD changer Where can I Find / buy Pioneer CD Sync Cable? Is certainly a special cable for that as I have two cassette decks that I can synchronize with .... started recording on cassette tape again. Are the Japanese bidding internet sites valid? Hope someone can help me find such a cable, which I know will be difficult. Kind regards Stefan
I seem to recall having a Garrad record-player, that had a 16RPM speed. Has anyone else seen one of those? It went 16/33.3/45/78 speed wise. 16RPM 12" records would have had a good long-play ability, but the only record I EVER found with a 16RPM track, was a comedy record, normally played at 33.3RPM, to create 'Chipmunks' audio. My Garrad deck was the only deck that could play the 'Chipmunks' section at normal speed. ;)
The lengthiest non-Trimicron 33 RPM LP I know of is Todd Rundgren's Initiation (1975) which was over 75 minutes and it too had the dynamics reduced and it required a good diamond tipped needle. But I didn't realize there were 33 RPM discs that were lengthier than the Rundgren LP until now.
I'm guessing the last bit was an afterthought, but it's just music and old video clips so does make the end of the video more useful and palatable and is perfect for an afterthought. Also, it keeps people from jumping to another video too quickly.
I used to use this method to record lots of music onto a single cassette. I would buy 120min cassettes, then record two different audio sources for each channel. It allowed me to carry less cassettes in my walkman.
One of the most iconic recordings of Beethoven's 9th - conducted by William Furtwangler in Bayreuth, 1951 is exactly 74 minutes long. Perhaps Sony's boss was a fan of that particular rendition, which is not that big of a stretch - many classical music buffs consider it best recorded version.
I expect the whole topic was discussed endlessly by engineers and management both, for months of years on end. Karajan was hugely influential and involved in the launch, Beethoven’s 9th was hugely popular, and Furtwangler’s was the longest known performance among recordings. I think the obvious goal all along was some balance between perfect sound quality, compact size (could fit in a shirt pocket, perhaps), and playing length (could fit any of the most popular albums on a single disc, including the longest known recordings of the very popular Beethoven ninth). It’s ridiculous to think these various discussions never took place, even if we lack documentation of any particular one.
Seems like that Trimicron disc is utilizing the lateral motion of the stereo stylus and creating an Edison style Z-Axis encoding for the audio in a straight walled grove that would move the stylus up and down but cause travel to the right and left while it is being pushed out of the grove. To get the density that grove would have to be immensely shallow and narrow... and I'd be curious as to how much real separation you get between the channels.
its less complex; they basically reduced groove amplitude 3-6 dB in order to pack twice as many of them on a record, 3-6 dB less amplitude means all the grooves need 50-75% less space and should look unnaturally straight, wich they indeed seem to do in the macro picture!
In line with my thinking. Shallower grooves in the vinyl reduces amplitude of the sound but enables closer spacing between the grooves for a longer record.
The above lp was a live classical recording, which as you know has a lot of bleed over. I checked for that myself, and it was inconclusive. On ting I didn't like is it is a bitch to keep clean. I had one dust spec that will not come out, and the needle skips when it hits it
I imported a few VCDs from Hong Kong a long time ago, and they did the same thing but with languages. Mandarin on the Left Channel, Cantonese on the Right.
The MPEG audio standard used for those did include the option of encoding stereo as effectively two entirely separate mono tracks (which has a specific meaning in how the encoder operates distinct from even the usual "straight stereo" option, which shares the bitrate between them and could end up accidentally starving one of the mono tracks of bits in a way that wouldn't be obvious when listening to a regular stereo track but stand out a mile in twin-mono... both being very distinct from Joint Stereo of course), for that very reason i.e. dual language recording, and pretty much anything I've seen capable of playing VCDs, and quite a lot of TVs of the era when they would have been popular, has a L/R/Stereo switch or option (even some VCRs). Though, VCDs being what they are, I can't help thinking the authors may have blithely encoded the track as rotten old Intensity Stereo anyway (which is meant more for expanded-mono / very limited stereo-field music) and effectively murdered the quality of both channels...
"Without forgetting" is fine (it just means "remembering") but it should only be used when the instruction is being clarified or repeated, not when being given for the first time.
This was also used for awhile for audio books. A special cassette player with a left and right switch allows the four tracks to be used for four mono channels.
The CD and the switcher did have a nice long life here in the US but only in a limited area. Audio books. I used to get them from the library with the switcher and I would have to crawl under the dash to hook it to my car radio. lol They used the same technique on cassette tapes. Love the channel, reminds me so much of all the kewl stuff we used to have. :)
its like a breath of fresh air watching your videos. the production quality is just so much higher than any other indie youtuber. your hard work and content are extremely appreciated. thanks
MJ was not only an impeccably talented artist but was also a staunch no-compromise audiophile to boot. In my opinion, one of the characteristics of his legacy that really set him head and shouldersabove and apart 99% of his “peers” or closest equivalent. He wasn’t satisfied simply creating great pop music. It had to be technically amazing as well.
Totally true. That's why we got the shortened "Lady in My Life" and the slightly-shortened "Billie Jean". "Billie Jean" can be heard in its full-length version on the 12-inch of the single. The only way to hear "Lady...", other than here on TH-cam, was on a Rod Temperton publisher's disc.
He didn't want to either. Quincy and he intentionally set out to create a record that would outsell "Off the Wall" and win him even more respect than that album and already earned him and every move they made for "Thriller" was hyper-calculated. Releasing a double album would have compromised sales and that wasn't going to happen.
Theoretically a CD has enough room for more audio than 74mins but there's space reserved for data (ROM) at the start (near center of CD) that is for decoding it. With developments, newer CDs would use more of this reserved ROM space used for copyright-protection encryption. If you regularly burn CDs as I do (providing audio of my church's services to those less tech savvy), you'll know a CD-R is 80mins but in reality the max is slightly less than that, but only because of the small amount of data used when burning you own CDs with no encryption. However, that 79mins (approx) will be further reduced by the more info you add to a CD (eg; titles, attributing artists, songwriters & technicians, copyright, etc.)!
MrWombatty Not sure you are getting the technical details right. Sure, this may be the garbled information that ended up in the user guides and online tips for the tools you use, but from what I have gathered, the situation is slightly different. For example the only copy protection and information that is supposed to take away any significant space are the ones that combine a CD-ROM and a music CD on the same disc, splitting the room between them with a slight gap. Titles and track information should take much less than 1 second of space provided the entire disk is burned in one pass, without stopping the recording process between tracks (as was common with some software to deal with a slow computer). Another thing is the difference between full size 80 minute blanks and the 74 minute blanks commonly sold. This was a deliberate limitation to make cheap blanks for computer backup useless for copying full commercial music CDs that made sure to exceed the shorter limit. Of cause computer backups really need every megabyte they can get, so soon it became easy for those in the know to buy the full length blanks.
The German punk band "Die Ärzte" once released a 3 CD album "Wir wollen nur deine Seele" with the third CD being sort of a gag pack-in. This 8cm disc has 42 minutes of banter from concerts in between songs and is also split to the left and right audio channels. en.wikipedia.org/wiki/Wir_wollen_nur_deine_Seele
That CD reminds me of the tape reels we had as a kid of old time radio programs. They had a different program in the left and right channel. The tape ran at the slowest speed and held many programs on a single reel. Some old amps had switch setting for mono L and mono R.
Yah, you can pack the track slightly on a CD without violating the Red Book's tolerances on track separation. Very common for getting shorter double albums (
Fascinating topic, as usual! You mentioned that the English Wikipedia page did not contain any mention of Trimicron, but it looks like someone took on the duty of adding the missing content just today (you can see the Wikipedia edit history). I am betting it's one of your viewers, because I was about to do the same thing. Thanks, whoever your are!
At one point in the life of these CD's Rodolphe did issue the CD'd with a special switch box that you could plug into your amp to be able to have the left hand track played via both speakers and the then switch to the right hand track, I still have one somewhere. This series of CD's were only of old live Mono operatic performances.
This is one of the reasons I enjoy this channel. I get to learn about formats and such that I never would have heard about otherwise. Keep up the good work!
I'm proud to see the french part on Wikipédia , talking about Trimicron recordings ! B-koz I wrote It in 2012 :) :) Got 5 of those records , and it's reaaly hard to play them on basic equipement. It requires really silent turntables and brand new stylus . you have to increase the volume up, and set the bass and trebles fine .. But it works.. Thanks Techmoan ;)
I remember K-Tel & Ronco records they put 8 to 10 tracks to a side & you have to crank volume & you herd the record noise. The cassettes they made were low in volume also & they never used Dolby. When I use to copy them records to cassette I had to raise the recording level.
The CD format did not come with a mono mode, therefore you had to manually either listen to left or right channel. The true oddity is that there IS a bit to signal quadraphonic mode in the Red Book standard, its right next to "copyrighted" and riaa curve.
Eh, I wouldn't be too confident about that proclamation. Depending on who you believe, the never-used-in-anger, never-properly-defined Quad flag could have been used for all manner of different things. * One source suggests 32kHz 12-bit encoding (which only really makes any sense because that's what DAT and DV use to double their recording time - however, that's forgetting that they use _48kHz_ as their full rate, not 44.1, and are also a touch noisy in 12-bit mode; actually, CD would have to drop to _29.4kHz_ in order to fit 4-channel playback within the same data rate at 12-bit, and 29.4kHz 12-bit audio would be so inherently compromised that you wouldn't really want to bother with four discrete tracks of it - possibly the "front" tracks would be 32kHz and the "back" ones about 26.8kHz, still all in 12-bit, or maybe 32kHz 16-bit front and 16kHz 12-bit rear, but those would both be mastering and decoding nightmares)... there may here also be some confusion with the Sony Playstation "XA Audio" standard which cocks about with the CDDA standard to produce audio that takes up a quarter of the usual space by encoding it as 4-bit ADPCM at 39.6kHz (necessarily reducing the sample rate, albeit to one that can still hold almost a full 20kHz of bandwidth, because of the halfway house XA data format they used for AV material, which co-opted the otherwise redundant subcodes to produce a format that wasn't as high capacity as Redbook CDDA/VCD, but somewhat more robust, whilst simultaneously being a little less robust but higher capacity than vanilla Orange-Book CDROM) * another says a simple halving of the sample rate to 22kHz in 16-bit (again, the loss of headroom would seem to exclude this) * a third some exotic quadrature scheme where the main stereo tracks are only reduced slightly in quality and rear ones are generated from them using some low-bandwidth sideband coding * a fourth, that the disc would play at double speed and all four tracks would be in full quality, but play time would be reduced to no more than 40 minutes per disc, or maybe 45 with some abuse of the physical parts of the standard (which is, after all, probably still enough to encode any extant quadraphonic recordings without any side-flipping breaks, and is an easy enough limit for new ones to respect) * and yet others say it's just a way to signify to the relevant decoding hardware that the audio uses a more conventional quadraphonic type encoding as was used on vinyl discs, or was just starting to come into cinematic use with the arrival of Dolby Surround and, more relevantly for the stereo recording market, Dolby Prologic. The latter of which I've made a test encoding of for a VCD derived from a Dolby Surround master recording, and piped through a surround sound decoder both from the finished disc and just as plain audio on a CDR, and the results were, eh, pretty decent though not world-beating, but it certainly could have been a workable gimmick for late 80s/all-1990s CD players meant to be hooked into a full home cinema type soundsystem (and either equipped with their own decoder, or able to connect digitally to an amplifier doing the same for the whole system), had Philips not got cold feet on the whole multi-standard thing and decided that CD was going to be Plain Stereo, Sixteen Bit, Forty-Four Point One Kilohertz, And Nothing Else. However, at the end of the day, pretty much none of those original flags were ever used, and most of them were never properly defined. They seemed to be left in there as Things To Fill In Later, and no-one ever got round to finishing the job before the standard was published, nor updating it later, even as stuff like CDROM, CDi, VCD, CD+G, CDExtra, CDText, CDXA got bolted on to the standard with their own "books". It's just a placeholder. Someone on the board probably said "well, what if someone wants to convert one of their old Quadraphonic releases to CD, what then?" (as well as "we need some way to signal copy protection to stop people copying their CDs to tape!" and "what if someone tries to master their pre-emphasised tapes that were previously used for cutting vinyls directly to CD? the player needs to be able to apply phono de-emphasis!", amongst other daft, management-level suggestions), and the one representative of the engineering department allowed into the meeting sighed in a resigned manner and said "OK, I'll add it to The List Of Desired Features" (sotto voce: "that we'll pencil in at the bottom of the spec just in case one of your guys ever looks at it, but never bother properly defining because it's a complete dead-end that will never be used, as, amongst other things, Quad was a failed idea that no-one has a decoder for"), telling his similarly dejected colleagues "guess what, we got Another One" on return to the workshop, promptly sticking it on the list of wouldn't-it-be-nice-if's, then ignoring it in order to get back to work fixing the myriad other much more important problems that stood in the way of them delivering the core product of a workable 20+kHz 80+dB dynamic range fully-independent-stereo optically-read five-inch digital audio format by the projected launch date.
J3608 ... I'm not sure entirely what you mean by any of that, but... as far as I understand it, most Quadraphonic systems (other than any which might have used two needles in separate synched grooves, or four wholly separate channels of an audio tape) simply used some kind of quadrature/phase encoding of stereo channels. A bit like how colour encoding works with a TV signal; the difference between the luma and chroma themselves is a simple bit of filtering and subcarrier coding / frequency splitting, but the chroma signal itself carries two distinct parts which are located in a notional 2D space by using their phase difference from the central carrier frequency (it's not quite FM - the overall frequency stays the same, but the encoded signal leads or lags the idealised pilot by a certain amount, as well as varying in amplitude, the two things together producing the overall value). Which, so long as you have sufficient bandwidth within your audio signal to allow the detection of the fairly minute, usually very high frequency differences between each channel that encode the additional channels, can be happily carried on a stereo system. Possibly CD might not actually have had enough bandwidth to actually pull it off, but maybe the phasing would have been crammed into the top 2kHz of the overall spectrum that was, at least theoretically, always meant to be kept unused to help prevent aliasing problems. Most classic quad systems as I understand it attempted to produce two wholly different additional channels, which was generally a step too far and led to crosstalk and eventual failure once the disc wore down a little and lost the high frequencies. Dolby ProLogic which came along in the 80s, and would have been a much better match for CD if it had been used in any more than a sparing few demonstration-grade discs (instead having more more use for TV broadcasts and videotape, as well as a few videogames) and Philips had in general given it the nod, used a somewhat more robust and less demanding system of mid/side type encoding to embed more overtly "surround" type effect channels within the stereo image, one "centre front" and the other "centre rear", quite easily generated from even an MPEG-encoded version of the original audio... so long as that was purely frequency-domain coded (like MP1 and MP2) and used non-destructive encoding of the stereo field, that is (separate stereo good, joint stereo still ok though you lose the bitrate efficiency benefits, intensity stereo very bad). In terms of discrete channels, CD, like vinyl, only ever had two. If you wanted more discrete channels than that, you had to use a 4-track (as in, portable studio) tape recorder, or a modified 8-track (as most only had two playback heads). Or two CD players with perfect synchronisation. Or, ultimately, DVD audio, or other multichannel options (including full Dolby Digital and DTS) from the late 90s onwards.
Splitting a stereo track in two forced the listener to jump through absurd hoops but... I kind of like the idea. Not because the idea itself is particularly good but because it shows how creative people were decades ago. The limits of technology lead to wonderful innovations.
I remember this split-channel technique, or something very much like it, being used on books-on-tape from the 1980s. It was kind of irritating, since most of the time my family listened to them on long car trips. At first, our car didn't have a way to adjust the audio balance at all, so we'd have to jam a pillow in front of one of the speakers to muffle the output. Later, with a new car, we could turn down the left or right channels, but not specify mono audio, so half of the book would be coming only out of the left side of the car, and the other half would only be coming out of the right.
When I was in highschool I made exactly this. I recorded a compilation of my favourite tracks, matching the lenghs (more or less) one into each chanell and then a little switch to toggle between them sending the mono signal to both ears. Until now I thought it was my original idea lol. It was usefull though, because I had twice the capacity and I only carried one disk
That guy on the Tri-Micron record sleeve looks like he bathes in cologne. BTW we used to do that left / right mono tracking bit back in the 60's and 70's with reel to reel machines. Record everything in mono on track 1, flip the tape over and do track 2, flip and do track 3, flip and do track 4.
Hey Mat, if you're reading this, I propose you run the "Block" skit whenever too many people complain about not seeing the puppets for a long time. That should tide them over.
In the 1960's, Wollensak's popular open reel recorder came out with a model that was designed to take advantage of the 4-track format if all you wanted to record was mono, like dictation. A wheel on the head cover allowed you to move the head vertically so that 4 sequential mono recordings were possible, flipping the tape at the end of each pass, somewhat like your 2.5 hour CD.
stpworld here's same problem, got the notification nearby a day later at 22nd of July at one thirty. I was wondering why he would upload it so late, but probably for north American audience.
Never happened to me with Techmoan yet, but i can confirm, sometimes TH-cam will just not notify you even for channels where you subscribe with a bell. It's just an unreliable system.
This is a general "thank you" for reconnecting me with the high fidelity hardware and media of my youth. It always cheers me to see the Techmoan notification.
I owned two such machines. You had to play the cassette right through, then go back to side 1 or A or whatever, and then flip a switch to get the rest. It was good for very long audio books.
It's also how Atari designed their cassette recorder for program storage on their early home computer systems (400/800 & XL series; Commodore and some of the others at the time might have done a similar thing). One channel was the recorded 300 baud modem audio, and the other channel was usable for audio narration, tutorials, or music if you really wanted to.
The CD reminded me of talking-book-for-the-visually-impared technology, e.g., when they string out a 4 hour long book read over the 4 separate tracks on a C-120 cassette. The record makes sense too... if the modulation levels are kept low then the grooves will not be so wildly wiggly and one can squeeze more grooves into the spaces between them and achieve more play time. Applied Science... thinking of that channel always makes me smile... I recall the first video series I saw from there was the home-made scanning electron microscope that Ben built from recycled/repurposed junk parts. That is incredibly awesome. Years ago I built from junk parts a 14 tube ((aka '14 valve' or '14 chube' ;-) )) radio transmitter/receiver for the 40 meter amateur radio band and I thought that was pretty cool, but that home-made scanning electron microscope is the ultimate of awesomeness for home-made stuff. :-)
I'm guessing when that record came out, less and less players had the 16 2/3rpm capabilities, because THAT'S how they used to get those long pieces of music on record. Those old classical music recording had low dynamic range so they sounded just fine at 16 /23rpm. In fact, they probably sounded BETTER than those 33 1/3 compressed quiet grooves.
I love the new credits scene. I usually would skip the credits as I don't care to see the Patreon list but now I'll watch them for the additional information you provide.
The other channel is in italian (my native language). I do suppose that "without forgetting" is a literal translation of "senza dimenticare" ... which means "don't forget" :D
It seems to be a literal translation from french of "sans oublier" wich mean "don't forget'. I would have made the same mistake many years ago. The problem with French is that they think they speak English. French-canadian know they speak nether... ;-)
True, I also noticed that in the very beginning was in French But I was disoriented because: the French duration is few seconds. Then it switches to italian in one channel and the English and Italian have a much longer duration. Initially thus I thought I was wrong to understand it was "French" ...
I remember when I was at RNW the engineers in the transcription service were approached by people of this format. So if a 2 hour hour concert was on 2 LPs with A, B, C and D sides could be on one disc. Well put it this way our engineers were not impressed with sound when it was demonstrated at our studios. Not impressed to the point where they were laughing. The experiment they tried was playing it 10 times in a row, the sound quality dropped dramatically and considering transcription discs were posted out to hundreds of radio stations by post there was always the risk of some damage. And if we had sent out these the risks would have been greater. Also you never know how the condition of the turn tables were at the various stations that use to receive the discs.
Fascinating video! I'd just add that me and my best pal clubbed together and bought a 180g vinyl of Making Movies in 1980, as his dad had a ridiculous high-end separates system. So heavy-grade vinyl has been around an awfully long time!
I remember authoring CDs back in the 90s and being frustrated that the redbook standard didn't allow for a mono recording with double the length. Would have been great for spoken-word content.
I agree. It's unfortunate that they didn't adopt something that was common with Laserdisc (LD): the ability to choose audio channels. With LD you could play the Right Channel, Left Channel, or both for stereo. Plus, when they added digital audio tracks you could do the same with them, giving you four separate audio programs on one disc. This ability was often used with anime, where the digital audio contained the original Japanese dialog and the analog tracks contained the English Dub. Since it also contained subtitles you didn't have to choose between a dubbed only or a subtitled only like with VHS tape.
Interesting fact. Monty Python's Vinyl Album Matching Tie and Handkerchief was classed as a three-sided album as on one side depending where you put the stylus you got two different sides as instead of a continuous groove it had two concentric grooves.
I was playing this the other day! It's originally a 1973 pressing. I noticed that the overall volume of the Side B & C is noticeably lower than the conventional side A, despite which even a small amount of dust can lead it to jump between side B & C... and from the outset, listening to the side you want can take a few goes... added to which each side has the same label you have a gloriously annoying record! (NB there are some later pressings/reissues/remasters that might have improved tech but I can't comment)
I love you and yer show and have for some years now. Cracked me up a bit when you said that might be the only way to listen to that long of a recording with that reel to reel in the top right of the frame. Again, great show.
3:35 I guess you are right about it being translated from another language. My guess is German. First of all, the guy has a slight German accent (mine is like that), secondly it is a recording by the Wiener Philharmoniker (Vienna Philharmonic Orchestra) and, last of all, this construction is typical for German and I as a native speaker would use it...and yeah maybe also translating it this way. No matter what, the instructions suck anyway. Doubt they are much better in German :D
not everyone, i'm italian, the PIZZA IS EVERYWERE! p.s:italians don't always say pizza, when we say every time pizza is for joking about italian stereotypes.
Thanks for the terrific video. I have a recent commercially available CD that contains almost 83 minutes of music. How peculiar--especially considering it seems to work perfectly. I'd thought that 80 minutes was the maximum for commercial audio CDs.
It's strange that CD standard was limited to only 2-channel 16-bit 44kHz PCM streams. Hardware capable processing such streams could also do 8-bit and variable sampling rate, 8-bit 11 kHz would still be good enough for speech and could store up to 8 hours on CD. Ideal for audiobooks. There was also ADPCM compression that could do up to 16 hours on a single CD. The only reason I can think of is to force CD-Audio as a high quality standard. 22 kHz sampling has quality of FM Radio, and 11 kHz is similar to AM Radio. DVB designed much later for digital broadcasting introduced flexible data container that proved to be future proof. Early 90's standard can support 4K and HDR or highest quality audio streams known to man. Fun fact, MP3 that became ultra popular in late 90's were a part of an initial DVB standard that used MPEG2.
Why, it makes sense if you remember when CD Audio was released in 1982 and must have been realisable with mostly essentially late 70s technology. The CD runs lock sync with the output with motor speed adjustment, so they only have to buffer maybe 20-35mm of pickup travel worth of data, much less than a full revolution. You can't make the CD spin arbitrarily slowly, as a particular minimum rotation speed is required to balance the disc. Had they wanted to make use of fractional data rates, they would have potentially had to buffer a whole revolution worth of data, or at least more than half a revolution, i.e. about 200mm worth of pickup travel on the outside of the disc.
The original CD standard was designed to be possible to decode on very simple fixed function hardware. Adding half bitrate or half samplerate capability would've required ADC circuitry modified to handle it, a drive that could spin at half (or quarter) speed or enough RAM to build a decent buffer, logic to detect when a disc wanted half/quarter rate playback. The original DVB spec isn't used for 4K/HDR, it's replaced by the incompatible DVB-S2/C2/T2.
It's easy to forget that the sub-$10 SOC embedded systems of today could match or even outperform a $1,000+ high-end home PC from 1980, when the original CD Audio standard was designed. It was certainly possible to make decoding hardware that would perform to those specs, but making something that would switch between differing formats, let alone in real time (variable rate), or performing relatively complex multiplications (for consumer hardware of the day) at a sufficient speed (ADPCM), would have put player production costs through the roof. So they settled on the best compromise of media size vs. playing time vs. general-purpose sound fidelity vs. playback unit construction cost.
This sounds like the tactic Sony's MiniDisc employed to expand its recording capacity, which they called "MDLP" (MiniDisc Long Play). They head 3 settings : 1. The regular capacity (aka SP) recording mode 2. MDLP 1 doubled the disc's original capacity (60mins = 120 ; 74mins = 154 ; 80mins = 160) 3. MDLP 2 quadrupled the disc's capacity (60mins = 240 ; 74mins = 308 ; 80mins = 320) However, to achieve this, the sound quality was compromised, where the standard default mode was recorded at about 256kbps quality (which is pretty good) ; recording in MDLP 1 cut that in half (to 128kbps, which is the minimum MP3 quality you want without losing too much quality) in order to double the recording time ; and likewise with MDLP 2 where it was divided again so you got the crappy and tinny-sounding bit rate as low as 64kbps (96kbps is the absolute lowest you'd ever wanna go before your music turns to total crap). The only useful mode was MDLP 1 so you could fit twice as much on a single MD, but still losing some sound quality. The best solution was the Hi-MD which offered a much broader range of recording modes and sound quality. For me, I can get just under 8 hours of music on a single Hi-MD at a bitrate of 320kbps. That's enough music for a whole (working) day without having to change the disc, and that's assuming you play the whole program through uninterrupted. Consider you may stop or pause it now and then, it'll give you enough tunes for your whole day, including transit time or whatever. Too bad the CD could not have a similar Hi-MD capability even if that meant it would only playback on special CD players, like the Hi-MD which of course needs to be played back on Hi-MD players only (regular MDs, even those recorded in MDLP 1 or MDLP 2 mode, is backward compatible with Hi-MD players).
That was a tricky thing by the Pythons. It had two completely different groves cut on each side, with different material recorded in each. I think it'd be a neat subject for its own video; I don't know if anyone else did it.
These are called "puzzle records" and they've been around as long as there have been disc records. Search TH-cam for "puzzle records" and you'll find several more, mostly from the 78 rpm era. One of the most common versions is a horse racing game, which typically has 6 interwoven tracks. You "bet" on which horse will win, then play the record to find out which horse won.
Kate Bush did this on her The Sensual World 12" single (www.discogs.com/Kate-Bush-The-Sensual-World/release/483472). Depending on where the stylus landed, you would hear either the vocal version or the instrumental version of the track.
High quality content presented in a highly skiled manner. That's why I like watching your videos even if the topic does not interest me that much! My girlfriend nearly said the same thing to me about your videos the other day.
Brilliance Audio (an audiobook publisher) used the same idea of dual mono channels in their Bookcassette system. Play sides A and B listenng to just the left channel, then play the tape again listening to just the right channel. Before this, unabridged audiobooks on cassette would be prohibitively expensive, and were generally limited to the library market* or aimed at services for the visually impaired (RNIB, for instance). Brilliance also sold a headphone adapter so stereo Walkmans and the like could play these books - a stereo/mono switch, essentially. Sometime later, Brilliance Audio actually championed an MP3-CD audiobook standard and sold a portable disc player with extra controls dedicated to navigating within the audiobook. *The reason library editions of audiobooks are significantly more expensive than the retail versions is because they come with "insurance" - the library can order replacements for individual damaged tapes or discs without having to replace the whole book.
I liked that little footnote bit during the Patreon credits; it's a nice touch that adds in a little bit of "extra information," even if it's not strictly about the topic of the video. I personally didn't know that the Beethoven's 9th story was an apocryphal one, nor was I aware that the symphony is actually shorter than a normal CD's lowest possible storage capacity.* Guess that shows just how much I know about CDs despite having gotten into the habit of collecting them in recent months. :P *For those reading this who are unaware of the following, CDs can store up to 99 minutes of Redbook audio nowadays thanks to the same techniques that produced that abnormally long 1980's compilation LP. Of course, nobody outside of a select few CD-R manufacturers actually makes CDs of that length, given that there's only a very small minority of popular music albums/recordings that surpass 74 minutes.
Seems pretty alright to me. It was mono audio in the first place, after all. And CD players were a hifi thing al those years ago, so left/right mono buttons etc were normal.
Agree, I'd be hard pressed to find any gear that has switches on it for one channel only playback. I do have an old amp with a mono switch, but it just mixes both channels together to give you mono, it would not help at all with this CD. Good job CD's are on the way out, muti-hour Mp3's etc. are no problem these days.
I'm just astonished that the audio CD specifications didn't have a standard Mono format. Just a quick flag at the start of the track that tells the player "yo this is in mono" and it could be played back accordingly.
The first thing I'd suggest to get double the time, would be to record on both sides. The second thing I'd say would be separate L and R. Up to 4x already without any clever stuff! EDIT: these are my ideas before watching ;)
+Paul Sengupta Dual sided CDs actually violate the Redbook standard, which requires a CD to be 1.2 mm thick, with the polycarbonate layer being thicker than half of that (don't remember the exact thickness requirement). Making a two sided CD impossible within the standard. Philips has even said that some DVD's which had a second side as a CD, couldn't use the CD logo on them, or that it would be copyright infringement. I remember reading up on this a long time ago, as I was an electronics service technician. Edit: Just found this info about the dual sided DVD/CDs en.wikipedia.org/wiki/DualDisc
Look at it as a way of speed optimizing your listening experience. You can listen to the whole recording in half the time without altering the playback speed - revolutionary!
"Welcome to the new generation of CDs", where you have to figure out how to mute one of the channels and then mute the other one an hour later.
LOL. A weird experience provided by the creative minds of those years, but remember the scarce resources they had.
Given how early this was, all CD players at the time would be high end audio equipment - meaning that they'd have balance controls, as well as equaliser dials, etc. So honestly it would likely have been easier then than a few years later when cheaper CD players that played cds and had either presets instead of a graphic equaliser or no equaliser settings, meaning they'd have no balance control either.
It's kind of a product of its time.
Unless you had a Beolab 5000 amplifier. It could play the two channels individually via a selector on the front.
No clue how you don't have your own series on BBC or Discovery Channel, your videos are better than most on TV....
the reason is that TV sucks
If Mat was on TV, the damned producers would ruin everything. Again, I'm left to wonder why the fuck people think being on TV is better. If this channel was only on BBC, I (an American) would be out of luck. TH-cam has more reach, because it has no region.
People, stop wishing that TH-camrs were on TV. If they were, they'd just turn into more shit TV.
@@md_vandenberg. Actually television currently has more reach globally than TH-cam for the simple reason more people have access to television worldwide than the internet.
Because if it were on any TV format (with TV producers and the people paying for TV, the advertisers) they would want to skew it to their own benefit, read that as "say what we tell you say not the truth" and then we are back to the same silly Bullshit that's; on the Tele already...Here on youtube he can say what he feels is true with out some one telling him what to say. I have a desk top tied to my 65" television, HD video and adequate sound quality. No need for TV at all.
The BBC wouldn't hire him. Too old, too white and too male.
I remember reading about a USA FM radio station in the 80's that was in a town that had two high schools. Both schools wanted to broadcast their football and basketball games on the same station, but their games happened around the same time. So the station compromised by putting one school's game on the left channel and the other school on the right channel.
wildbilltexas I remember radio stations trying this in the ‘90s. It was also for two football games at once.
Well that's a shitty idea, the crosstalk must have been horrendous. The reason is that FM broadcasts the L+R signal and L-R signal, and L-R is off to the side of the band and more subject to degradation.
Siana Gearz Both games were limited to about 5kHz as was normal then. It worked, but sounded weird, and you were out of luck if you had a mono radio!
They still do on an FM station from the Liberty Dayton area of Texas
When I was a radio DJ in the 80's-90's they used regular phone lines for the feed from the stadium or the gym. Some stations still do that, but many are using the internet now.
The diagram in the Trimicron record jacket misled me at first, until I started thinking a bit more 3-dimensionally about it. Since the stylus rides on the sides of the grooves, and not the top or bottom, it doesn't actually matter if the very top of the groove has a different shape than the audio deeper in the groove (where the stylus actually touches). Since grooves are V-shaped, the deeper into the groove you go, the further away from the next groove you become. The one constant is that the sides of the groove need to be 90 degrees from each other in order to be compatible with normal stereo styli.
Because the 90-degree angle has to remain, that means the closer you want to pack the grooves to each other, the shallower they have to become. This would, of course, explain the reduced amplitude (the stylus has less material to ride against) but also means that, since the stylus would be riding "higher" in the groove, the tip of it would actually be what picks up the audio, instead of the sides (since styli are somewhat cone-shaped). This could lead to reduced stereo separation, as Fran Blanche mentioned in another comment here (hi Fran!).
The Trimicron system simply seems to have come up with the smallest possible ratio between groove pitch and depth such that there's sufficient amplitude, but also the minimal distance between grooves where the stylus rides. Not a horrible idea, really, though it certainly has its drawbacks.
This Does Not Compute I would imagine that it actually does have an effect. My guess is that it is the cause of the reduced dynamic range and audio levels,as the needle has less room to move.
+This Does Not Compute Now you know something about it! I was thinking about the size and length between a vinyl record and a CD, especially the whole album filled with songs too. I thought that a vinyl record will last 1 hour to make a full album just like the CDs from a long time ago.
This Does Not Compute incredible explanation! I've also experienced this change in a few records I own.
I've had a Fleetwood Mac Greatest Hits record for a while now, and I recently found a copy of their album "Rumours." I've noticed quite a difference in amplitude and depth that's obviously due to the amount of surface area that each track takes up. The track I used for reference was "Dreams."
This technique certainly has its drawbacks. Because the recordings are much more quiet, you are much more prone to notice higher levels of surface noise and crackles as a result. Okay for "throw away" compilation albums that are not very important, where a record is expected just a few plays in its lifetime; but something not to be considered for prized and important record releases though. The sound quality degrades at a much faster rate due to stylus playwear and contamination from dust, dirt and mishandling issues.
hey Colin!!
You always find the most obscure but interesting media formats.
These aren't media formats, since you can still play on normal CD players and record players. Just mono stacking for the CD, and reduced amplitude and dynamic range to squeeze the grooves closer together for vinyl. K-Tel records did this all the time to pack songs onto vinyl, but the songs sound flat as a result.
Buzzkill.
Hey ! Is about to buy model Pioneer PD-TM 1,2,3 CD changer
Where can I Find / buy Pioneer CD Sync Cable?
Is certainly a special cable for that as I have two cassette decks that I can synchronize with
.... started recording on cassette tape again.
Are the Japanese bidding internet sites valid?
Hope someone can help me find such a cable, which I know will be difficult.
Kind regards
Stefan
@@nullunit5566 subformat
I seem to recall having a Garrad record-player, that had a 16RPM speed. Has anyone else seen one of those? It went 16/33.3/45/78 speed wise.
16RPM 12" records would have had a good long-play ability, but the only record I EVER found with a 16RPM track, was a comedy record, normally played at 33.3RPM, to create 'Chipmunks' audio. My Garrad deck was the only deck that could play the 'Chipmunks' section at normal speed. ;)
"Sounds like the kind of thing someone would come up with on Kickstarter."
HA!
I read this comment in the exact moment he said it lmao
"Instructions Unclear - CD now stuck in Amplifier" hahahaha
Keep your disk in a vise!
You mean di*k stuck in amplifier? (I don’t know why I had to sensor the word disk).
Frank Winkhorst Who or what?
Brilliant!
"Directions unclear - CD stuck in amplifier" had me in stitches. Techmoan has done it again!
The lengthiest non-Trimicron 33 RPM LP I know of is Todd Rundgren's Initiation (1975) which was over 75 minutes and it too had the dynamics reduced and it required a good diamond tipped needle. But I didn't realize there were 33 RPM discs that were lengthier than the Rundgren LP until now.
I like the new style of the ending !!!!
A revolutionary new generation of ending!
JAM HOUSE same lol, i kept getting the urge to tap it to full screen.......
Same!
I fairly sure it has been like that for a while.
I'm guessing the last bit was an afterthought, but it's just music and old video clips so does make the end of the video more useful and palatable and is perfect for an afterthought. Also, it keeps people from jumping to another video too quickly.
I used to use this method to record lots of music onto a single cassette. I would buy 120min cassettes, then record two different audio sources for each channel. It allowed me to carry less cassettes in my walkman.
It is worth noting that the left/right trick is used to switch between vocal and karaoke versions of songs in some systems.
One of the most iconic recordings of Beethoven's 9th - conducted by William Furtwangler in Bayreuth, 1951 is exactly 74 minutes long. Perhaps Sony's boss was a fan of that particular rendition, which is not that big of a stretch - many classical music buffs consider it best recorded version.
I expect the whole topic was discussed endlessly by engineers and management both, for months of years on end. Karajan was hugely influential and involved in the launch, Beethoven’s 9th was hugely popular, and Furtwangler’s was the longest known performance among recordings. I think the obvious goal all along was some balance between perfect sound quality, compact size (could fit in a shirt pocket, perhaps), and playing length (could fit any of the most popular albums on a single disc, including the longest known recordings of the very popular Beethoven ninth). It’s ridiculous to think these various discussions never took place, even if we lack documentation of any particular one.
Seems like that Trimicron disc is utilizing the lateral motion of the stereo stylus and creating an Edison style Z-Axis encoding for the audio in a straight walled grove that would move the stylus up and down but cause travel to the right and left while it is being pushed out of the grove. To get the density that grove would have to be immensely shallow and narrow... and I'd be curious as to how much real separation you get between the channels.
Fran Blanche Fran!!
Fran Blanche separation? What separation? 😂
its less complex; they basically reduced groove amplitude 3-6 dB in order to pack twice as many of them on a record, 3-6 dB less amplitude means all the grooves need 50-75% less space and should look unnaturally straight, wich they indeed seem to do in the macro picture!
In line with my thinking. Shallower grooves in the vinyl reduces amplitude of the sound but enables closer spacing between the grooves for a longer record.
The above lp was a live classical recording, which as you know has a lot of bleed over. I checked for that myself, and it was inconclusive.
On ting I didn't like is it is a bitch to keep clean. I had one dust spec that will not come out, and the needle skips when it hits it
I imported a few VCDs from Hong Kong a long time ago, and they did the same thing but with languages. Mandarin on the Left Channel, Cantonese on the Right.
Some early DVD players had the ability to select between Stereo, Left or Right modes. (In DVD mode it would select surround or stereo fold-down)
The MPEG audio standard used for those did include the option of encoding stereo as effectively two entirely separate mono tracks (which has a specific meaning in how the encoder operates distinct from even the usual "straight stereo" option, which shares the bitrate between them and could end up accidentally starving one of the mono tracks of bits in a way that wouldn't be obvious when listening to a regular stereo track but stand out a mile in twin-mono... both being very distinct from Joint Stereo of course), for that very reason i.e. dual language recording, and pretty much anything I've seen capable of playing VCDs, and quite a lot of TVs of the era when they would have been popular, has a L/R/Stereo switch or option (even some VCRs). Though, VCDs being what they are, I can't help thinking the authors may have blithely encoded the track as rotten old Intensity Stereo anyway (which is meant more for expanded-mono / very limited stereo-field music) and effectively murdered the quality of both channels...
Also, on karaoke VCDs, you have the vocal on the right channel and the instruments on the left.
About the "without forgetting" bit, you are spot on, it is an Italian expression ("senza dimenticare di") that can be translated as "don't forget to".
It's the same in German.
"Without forgetting" is fine (it just means "remembering") but it should only be used when the instruction is being clarified or repeated, not when being given for the first time.
One of my favourite channels on TH-cam. Why you don't have a legitimate television program is beyond me! Excellent!
This was also used for awhile for audio books. A special cassette player with a left and right switch allows the four tracks to be used for four mono channels.
The CD and the switcher did have a nice long life here in the US but only in a limited area. Audio books. I used to get them from the library with the switcher and I would have to crawl under the dash to hook it to my car radio. lol They used the same technique on cassette tapes. Love the channel, reminds me so much of all the kewl stuff we used to have. :)
The 2.5 hr cd's way of squeezing content remids me on how 8 tracks/ cassettes would work..
its like a breath of fresh air watching your videos. the production quality is just so much higher than any other indie youtuber. your hard work and content are extremely appreciated. thanks
It's amazing mechanical technology that went into creating records
That's why I love record players despite me being okay with listening to music on my phones using blutooth headphones. It's just plain cool tech.
Michael Jackson literally cried when he realized he had to cut down all his songs for Thriller to get the sound quality he wanted to fit on an LP.
And I'm guessing the suits wouldn't allow him to release a 2 LP?
MJ was not only an impeccably talented artist but was also a staunch no-compromise audiophile to boot. In my opinion, one of the characteristics of his legacy that really set him head and shouldersabove and apart 99% of his “peers” or closest equivalent. He wasn’t satisfied simply creating great pop music. It had to be technically amazing as well.
Totally true. That's why we got the shortened "Lady in My Life" and the slightly-shortened "Billie Jean". "Billie Jean" can be heard in its full-length version on the 12-inch of the single. The only way to hear "Lady...", other than here on TH-cam, was on a Rod Temperton publisher's disc.
He didn't want to either. Quincy and he intentionally set out to create a record that would outsell "Off the Wall" and win him even more respect than that album and already earned him and every move they made for "Thriller" was hyper-calculated. Releasing a double album would have compromised sales and that wasn't going to happen.
thegrimyeaper 2lp?
Another good video. Thanks for debunking the 74 minute story. I've believed that one for a couple decades.
It's weird how some things work themselves into facts but no one can remember where they came from.
Techmoan I remember reading that on Wikipedia and assuming it was true.
I was just about to make the same comment... I only hope most people see it instead of switching it off as soon as the outro starts.
Theoretically a CD has enough room for more audio than 74mins but there's space reserved for data (ROM) at the start (near center of CD) that is for decoding it. With developments, newer CDs would use more of this reserved ROM space used for copyright-protection encryption.
If you regularly burn CDs as I do (providing audio of my church's services to those less tech savvy), you'll know a CD-R is 80mins but in reality the max is slightly less than that, but only because of the small amount of data used when burning you own CDs with no encryption. However, that 79mins (approx) will be further reduced by the more info you add to a CD (eg; titles, attributing artists, songwriters & technicians, copyright, etc.)!
MrWombatty Not sure you are getting the technical details right. Sure, this may be the garbled information that ended up in the user guides and online tips for the tools you use, but from what I have gathered, the situation is slightly different. For example the only copy protection and information that is supposed to take away any significant space are the ones that combine a CD-ROM and a music CD on the same disc, splitting the room between them with a slight gap. Titles and track information should take much less than 1 second of space provided the entire disk is burned in one pass, without stopping the recording process between tracks (as was common with some software to deal with a slow computer). Another thing is the difference between full size 80 minute blanks and the 74 minute blanks commonly sold. This was a deliberate limitation to make cheap blanks for computer backup useless for copying full commercial music CDs that made sure to exceed the shorter limit. Of cause computer backups really need every megabyte they can get, so soon it became easy for those in the know to buy the full length blanks.
Two styles I never knew about before that doesnt need special equipment, thanks :)
The German punk band "Die Ärzte" once released a 3 CD album "Wir wollen nur deine Seele" with the third CD being sort of a gag pack-in. This 8cm disc has 42 minutes of banter from concerts in between songs and is also split to the left and right audio channels.
en.wikipedia.org/wiki/Wir_wollen_nur_deine_Seele
That CD reminds me of the tape reels we had as a kid of old time radio programs. They had a different program in the left and right channel. The tape ran at the slowest speed and held many programs on a single reel. Some old amps had switch setting for mono L and mono R.
Wonderful as always, Techmoan. One of the greatest channels in YT.
Remark: I own CDs which are 79 minutes in lenght.
Yah, you can pack the track slightly on a CD without violating the Red Book's tolerances on track separation. Very common for getting shorter double albums (
This is why I watch this channel. I never even knew that this existed. I have learned so much about obscure formats from Techmoen!
You forgot to edit in the explosion sound effect at 6:08
It becames a Shango066 video
Fascinating topic, as usual! You mentioned that the English Wikipedia page did not contain any mention of Trimicron, but it looks like someone took on the duty of adding the missing content just today (you can see the Wikipedia edit history). I am betting it's one of your viewers, because I was about to do the same thing. Thanks, whoever your are!
2:46 I lost it at "Instructions Unclear - CD now stuck in Amplifier"
Love this guy, quality informative thumbnail and video title. Hard to find nowadays!
At one point in the life of these CD's Rodolphe did issue the CD'd with a special switch box that you could plug into your amp to be able to have the left hand track played via both speakers and the then switch to the right hand track, I still have one somewhere. This series of CD's were only of old live Mono operatic performances.
This is one of the reasons I enjoy this channel. I get to learn about formats and such that I never would have heard about otherwise. Keep up the good work!
"Sounds like the sort of thing someone might come up with on Kickstarter"
I think I laughed way too hard at that line. Thanks, Techmoan!
I'm proud to see the french part on Wikipédia , talking about Trimicron recordings ! B-koz I wrote It in 2012 :) :)
Got 5 of those records , and it's reaaly hard to play them on basic equipement.
It requires really silent turntables and brand new stylus .
you have to increase the volume up, and set the bass and trebles fine .. But it works..
Thanks Techmoan ;)
I’m not a techie. But the way you present this stuff is so thorough and well done, this stuff is very interesting. Thank you.
I remember K-Tel & Ronco records they put 8 to 10 tracks to a side & you have to crank volume & you herd the record noise. The cassettes they made were low in volume also & they never used Dolby. When I use to copy them records to cassette I had to raise the recording level.
Wait a minute, Splitting 1 stereo into 2 mono tracks? Is this 4 or 8 track all over again for cd?
The CD format did not come with a mono mode, therefore you had to manually either listen to left or right channel. The true oddity is that there IS a bit to signal quadraphonic mode in the Red Book standard, its right next to "copyrighted" and riaa curve.
That shirt is freaking awesome!
All of them witches
Eh, I wouldn't be too confident about that proclamation. Depending on who you believe, the never-used-in-anger, never-properly-defined Quad flag could have been used for all manner of different things.
* One source suggests 32kHz 12-bit encoding (which only really makes any sense because that's what DAT and DV use to double their recording time - however, that's forgetting that they use _48kHz_ as their full rate, not 44.1, and are also a touch noisy in 12-bit mode; actually, CD would have to drop to _29.4kHz_ in order to fit 4-channel playback within the same data rate at 12-bit, and 29.4kHz 12-bit audio would be so inherently compromised that you wouldn't really want to bother with four discrete tracks of it - possibly the "front" tracks would be 32kHz and the "back" ones about 26.8kHz, still all in 12-bit, or maybe 32kHz 16-bit front and 16kHz 12-bit rear, but those would both be mastering and decoding nightmares)... there may here also be some confusion with the Sony Playstation "XA Audio" standard which cocks about with the CDDA standard to produce audio that takes up a quarter of the usual space by encoding it as 4-bit ADPCM at 39.6kHz (necessarily reducing the sample rate, albeit to one that can still hold almost a full 20kHz of bandwidth, because of the halfway house XA data format they used for AV material, which co-opted the otherwise redundant subcodes to produce a format that wasn't as high capacity as Redbook CDDA/VCD, but somewhat more robust, whilst simultaneously being a little less robust but higher capacity than vanilla Orange-Book CDROM)
* another says a simple halving of the sample rate to 22kHz in 16-bit (again, the loss of headroom would seem to exclude this)
* a third some exotic quadrature scheme where the main stereo tracks are only reduced slightly in quality and rear ones are generated from them using some low-bandwidth sideband coding
* a fourth, that the disc would play at double speed and all four tracks would be in full quality, but play time would be reduced to no more than 40 minutes per disc, or maybe 45 with some abuse of the physical parts of the standard (which is, after all, probably still enough to encode any extant quadraphonic recordings without any side-flipping breaks, and is an easy enough limit for new ones to respect)
* and yet others say it's just a way to signify to the relevant decoding hardware that the audio uses a more conventional quadraphonic type encoding as was used on vinyl discs, or was just starting to come into cinematic use with the arrival of Dolby Surround and, more relevantly for the stereo recording market, Dolby Prologic.
The latter of which I've made a test encoding of for a VCD derived from a Dolby Surround master recording, and piped through a surround sound decoder both from the finished disc and just as plain audio on a CDR, and the results were, eh, pretty decent though not world-beating, but it certainly could have been a workable gimmick for late 80s/all-1990s CD players meant to be hooked into a full home cinema type soundsystem (and either equipped with their own decoder, or able to connect digitally to an amplifier doing the same for the whole system), had Philips not got cold feet on the whole multi-standard thing and decided that CD was going to be Plain Stereo, Sixteen Bit, Forty-Four Point One Kilohertz, And Nothing Else.
However, at the end of the day, pretty much none of those original flags were ever used, and most of them were never properly defined. They seemed to be left in there as Things To Fill In Later, and no-one ever got round to finishing the job before the standard was published, nor updating it later, even as stuff like CDROM, CDi, VCD, CD+G, CDExtra, CDText, CDXA got bolted on to the standard with their own "books". It's just a placeholder. Someone on the board probably said "well, what if someone wants to convert one of their old Quadraphonic releases to CD, what then?" (as well as "we need some way to signal copy protection to stop people copying their CDs to tape!" and "what if someone tries to master their pre-emphasised tapes that were previously used for cutting vinyls directly to CD? the player needs to be able to apply phono de-emphasis!", amongst other daft, management-level suggestions), and the one representative of the engineering department allowed into the meeting sighed in a resigned manner and said "OK, I'll add it to The List Of Desired Features" (sotto voce: "that we'll pencil in at the bottom of the spec just in case one of your guys ever looks at it, but never bother properly defining because it's a complete dead-end that will never be used, as, amongst other things, Quad was a failed idea that no-one has a decoder for"), telling his similarly dejected colleagues "guess what, we got Another One" on return to the workshop, promptly sticking it on the list of wouldn't-it-be-nice-if's, then ignoring it in order to get back to work fixing the myriad other much more important problems that stood in the way of them delivering the core product of a workable 20+kHz 80+dB dynamic range fully-independent-stereo optically-read five-inch digital audio format by the projected launch date.
J3608 ... I'm not sure entirely what you mean by any of that, but... as far as I understand it, most Quadraphonic systems (other than any which might have used two needles in separate synched grooves, or four wholly separate channels of an audio tape) simply used some kind of quadrature/phase encoding of stereo channels. A bit like how colour encoding works with a TV signal; the difference between the luma and chroma themselves is a simple bit of filtering and subcarrier coding / frequency splitting, but the chroma signal itself carries two distinct parts which are located in a notional 2D space by using their phase difference from the central carrier frequency (it's not quite FM - the overall frequency stays the same, but the encoded signal leads or lags the idealised pilot by a certain amount, as well as varying in amplitude, the two things together producing the overall value). Which, so long as you have sufficient bandwidth within your audio signal to allow the detection of the fairly minute, usually very high frequency differences between each channel that encode the additional channels, can be happily carried on a stereo system. Possibly CD might not actually have had enough bandwidth to actually pull it off, but maybe the phasing would have been crammed into the top 2kHz of the overall spectrum that was, at least theoretically, always meant to be kept unused to help prevent aliasing problems.
Most classic quad systems as I understand it attempted to produce two wholly different additional channels, which was generally a step too far and led to crosstalk and eventual failure once the disc wore down a little and lost the high frequencies. Dolby ProLogic which came along in the 80s, and would have been a much better match for CD if it had been used in any more than a sparing few demonstration-grade discs (instead having more more use for TV broadcasts and videotape, as well as a few videogames) and Philips had in general given it the nod, used a somewhat more robust and less demanding system of mid/side type encoding to embed more overtly "surround" type effect channels within the stereo image, one "centre front" and the other "centre rear", quite easily generated from even an MPEG-encoded version of the original audio... so long as that was purely frequency-domain coded (like MP1 and MP2) and used non-destructive encoding of the stereo field, that is (separate stereo good, joint stereo still ok though you lose the bitrate efficiency benefits, intensity stereo very bad).
In terms of discrete channels, CD, like vinyl, only ever had two. If you wanted more discrete channels than that, you had to use a 4-track (as in, portable studio) tape recorder, or a modified 8-track (as most only had two playback heads). Or two CD players with perfect synchronisation. Or, ultimately, DVD audio, or other multichannel options (including full Dolby Digital and DTS) from the late 90s onwards.
Splitting a stereo track in two forced the listener to jump through absurd hoops but... I kind of like the idea. Not because the idea itself is particularly good but because it shows how creative people were decades ago. The limits of technology lead to wonderful innovations.
I got a 4k tv today and this is the first 4k video I've ever seen. Thought you'd like to hear that.
I just discovered this channel and im already amazed by how good this channel is!!
I remember this split-channel technique, or something very much like it, being used on books-on-tape from the 1980s. It was kind of irritating, since most of the time my family listened to them on long car trips. At first, our car didn't have a way to adjust the audio balance at all, so we'd have to jam a pillow in front of one of the speakers to muffle the output. Later, with a new car, we could turn down the left or right channels, but not specify mono audio, so half of the book would be coming only out of the left side of the car, and the other half would only be coming out of the right.
Haha, interesting.
As always, thanks for filming. Always interesting.
When I was in highschool I made exactly this. I recorded a compilation of my favourite tracks, matching the lenghs (more or less) one into each chanell and then a little switch to toggle between them sending the mono signal to both ears. Until now I thought it was my original idea lol. It was usefull though, because I had twice the capacity and I only carried one disk
That guy on the Tri-Micron record sleeve looks like he bathes in cologne. BTW we used to do that left / right mono tracking bit back in the 60's and 70's with reel to reel machines. Record everything in mono on track 1, flip the tape over and do track 2, flip and do track 3, flip and do track 4.
It's been too long since we had a muppet short! I've been reduced to hunting down reruns!
KarlBunker I was just thinking the same thing.
Oh, you mean the unfunny, childish & idiotic puppets? /s
mMUS people like you are the reason we don't have him anymore.
I was being sarcastic...
Hey Mat, if you're reading this, I propose you run the "Block" skit whenever too many people complain about not seeing the puppets for a long time. That should tide them over.
Loved the captions on the instructions. And so glad that I still have back videos to catch up on....
"Push the CD into the CD player." OK, now I have a broken CD and a massive cut on my hand. What's the next step?
Duh, press the mono button.
"Peel back foil to expose tater tots."
Go to hospital for stitches to hand.
The next step is "without forgetting". Always remember to never forget.
🙄
In the 1960's, Wollensak's popular open reel recorder came out with a model that was designed to take advantage of the 4-track format if all you wanted to record was mono, like dictation. A wheel on the head cover allowed you to move the head vertically so that 4 sequential mono recordings were possible, flipping the tape at the end of each pass, somewhat like your 2.5 hour CD.
Sometimes I don't get notifications of your videos. Then I miss 1or 2 and I try to watch when ever you have a new upload.
stpworld here's same problem, got the notification nearby a day later at 22nd of July at one thirty. I was wondering why he would upload it so late, but probably for north American audience.
click the bell icon next to the subscribe button then you won't miss any notification from TechMoan anymore
It is on does not tell me anyway sometimes.
Never happened to me with Techmoan yet, but i can confirm, sometimes TH-cam will just not notify you even for channels where you subscribe with a bell. It's just an unreliable system.
I checked mine at my smartphone and right around one forty five the YT-app showed "40 minutes" as time since upload.
Speaking of perfect lengths, well done getting that length of a CD explanation out so nicely in the time available in the outro!
"Dans la meme collection" 6:44
... You're welcome, I think.
From the same collection
même*
Dank meme collection
meme means same in french
This is a general "thank you" for reconnecting me with the high fidelity hardware and media of my youth. It always cheers me to see the Techmoan notification.
That is an old reel to reel trick to get double the information on a tape with two mono program selections per direction.
I owned two such machines. You had to play the cassette right through, then go back to side 1 or A or whatever, and then flip a switch to get the rest. It was good for very long audio books.
It's also how Atari designed their cassette recorder for program storage on their early home computer systems (400/800 & XL series; Commodore and some of the others at the time might have done a similar thing). One channel was the recorded 300 baud modem audio, and the other channel was usable for audio narration, tutorials, or music if you really wanted to.
The CD reminded me of talking-book-for-the-visually-impared technology, e.g., when they string out a 4 hour long book read over the 4 separate tracks on a C-120 cassette. The record makes sense too... if the modulation levels are kept low then the grooves will not be so wildly wiggly and one can squeeze more grooves into the spaces between them and achieve more play time.
Applied Science... thinking of that channel always makes me smile... I recall the first video series I saw from there was the home-made scanning electron microscope that Ben built from recycled/repurposed junk parts. That is incredibly awesome. Years ago I built from junk parts a 14 tube ((aka '14 valve' or '14 chube' ;-) )) radio transmitter/receiver for the 40 meter amateur radio band and I thought that was pretty cool, but that home-made scanning electron microscope is the ultimate of awesomeness for home-made stuff. :-)
I'm guessing when that record came out, less and less players had the 16 2/3rpm capabilities, because THAT'S how they used to get those long pieces of music on record. Those old classical music recording had low dynamic range so they sounded just fine at 16 /23rpm. In fact, they probably sounded BETTER than those 33 1/3 compressed quiet grooves.
I love the new credits scene. I usually would skip the credits as I don't care to see the Patreon list but now I'll watch them for the additional information you provide.
The other channel is in italian (my native language). I do suppose that "without forgetting" is a literal translation of "senza dimenticare" ... which means "don't forget" :D
The same with German, the English voice sounds a bit "German" anyway.
I agree with KWHBSN. Furthermore the recording is by the Vienna Philharmonic Orchestra. So a German original is quite likely.
It seems to be a literal translation from french of "sans oublier" wich mean "don't forget'. I would have made the same mistake many years ago. The problem with French is that they think they speak English. French-canadian know they speak nether... ;-)
Patrick Aubry "Without forgetting the fact that" the whole leaflet is in french, and that the explanation begins in french.
True, I also noticed that in the very beginning was in French But I was disoriented because: the French duration is few seconds. Then it switches to italian in one channel and the English and Italian have a much longer duration.
Initially thus I thought I was wrong to understand it was "French" ...
You're a funny chap😄 The subtext by the CD explanation was particularly funny. "..Lost me after 'new generation of CD' " Marvelous!
Damn it!! I spit my tea all over my phone when I read, "instructions unclear... My cd is now stuck in my amplifier".
:-)
It's a bit overused in places.
Instructions unclear, spit tea on phone
I like having you talk about the bonus trivia during the end credits. It'd be nice to see that return as a regular feature in your videos!
I remember when I was at RNW the engineers in the transcription service were approached by people of this format. So if a 2 hour hour concert was on 2 LPs with A, B, C and D sides could be on one disc. Well put it this way our engineers were not impressed with sound when it was demonstrated at our studios. Not impressed to the point where they were laughing. The experiment they tried was playing it 10 times in a row, the sound quality dropped dramatically and considering transcription discs were posted out to hundreds of radio stations by post there was always the risk of some damage. And if we had sent out these the risks would have been greater. Also you never know how the condition of the turn tables were at the various stations that use to receive the discs.
Keith Perron RNW = Radio Nederland Weltomroep?
Mattia D'ercole yes.
Fascinating video! I'd just add that me and my best pal clubbed together and bought a 180g vinyl of Making Movies in 1980, as his dad had a ridiculous high-end separates system. So heavy-grade vinyl has been around an awfully long time!
I remember authoring CDs back in the 90s and being frustrated that the redbook standard didn't allow for a mono recording with double the length. Would have been great for spoken-word content.
I agree. It's unfortunate that they didn't adopt something that was common with Laserdisc (LD): the ability to choose audio channels. With LD you could play the Right Channel, Left Channel, or both for stereo. Plus, when they added digital audio tracks you could do the same with them, giving you four separate audio programs on one disc.
This ability was often used with anime, where the digital audio contained the original Japanese dialog and the analog tracks contained the English Dub. Since it also contained subtitles you didn't have to choose between a dubbed only or a subtitled only like with VHS tape.
Techmoan is brilliant! I loved this video.
👍👍👍 For the Ming The Merciless reference!
FLASH! AHHHH!
I liked quite a lot of the idea of telling a related trivia during the Patreon segment. Great work all around!
Interesting fact. Monty Python's Vinyl Album Matching Tie and Handkerchief was classed as a three-sided album as on one side depending where you put the stylus you got two different sides as instead of a continuous groove it had two concentric grooves.
I was playing this the other day! It's originally a 1973 pressing. I noticed that the overall volume of the Side B & C is noticeably lower than the conventional side A, despite which even a small amount of dust can lead it to jump between side B & C... and from the outset, listening to the side you want can take a few goes... added to which each side has the same label you have a gloriously annoying record! (NB there are some later pressings/reissues/remasters that might have improved tech but I can't comment)
I love you and yer show and have for some years now. Cracked me up a bit when you said that might be the only way to listen to that long of a recording with that reel to reel in the top right of the frame. Again, great show.
That little story about Gizmodo doesn’t surprise me. Once a lazy clickbait website, always a lazy clickbait website.
Nice touch with the extra facts during the credits/Patreon call-outs, I like it. Fills out the video nicely.
3:35 I guess you are right about it being translated from another language. My guess is German. First of all, the guy has a slight German accent (mine is like that), secondly it is a recording by the Wiener Philharmoniker (Vienna Philharmonic Orchestra) and, last of all, this construction is typical for German and I as a native speaker would use it...and yeah maybe also translating it this way.
No matter what, the instructions suck anyway. Doubt they are much better in German :D
never mind all this... look at your separates setup in the background... amazing.... GREAT video as always mate.
not everyone, i'm italian, the PIZZA IS EVERYWERE! p.s:italians don't always say pizza, when we say every time pizza is for joking about italian stereotypes.
Its amazing you continue to find 'new' things to show!
great videos man. :)
Thanks for the terrific video.
I have a recent commercially available CD that contains almost 83 minutes of music. How peculiar--especially considering it seems to work perfectly. I'd thought that 80 minutes was the maximum for commercial audio CDs.
TIL that Onslow from _Keeping Up Appearances_ invented the Trimicron record.
Ming the merciless?! This was a great video before but that name drop immediately earned a like before the video finished.
It's strange that CD standard was limited to only 2-channel 16-bit 44kHz PCM streams. Hardware capable processing such streams could also do 8-bit and variable sampling rate, 8-bit 11 kHz would still be good enough for speech and could store up to 8 hours on CD. Ideal for audiobooks. There was also ADPCM compression that could do up to 16 hours on a single CD.
The only reason I can think of is to force CD-Audio as a high quality standard. 22 kHz sampling has quality of FM Radio, and 11 kHz is similar to AM Radio.
DVB designed much later for digital broadcasting introduced flexible data container that proved to be future proof. Early 90's standard can support 4K and HDR or highest quality audio streams known to man. Fun fact, MP3 that became ultra popular in late 90's were a part of an initial DVB standard that used MPEG2.
Why, it makes sense if you remember when CD Audio was released in 1982 and must have been realisable with mostly essentially late 70s technology. The CD runs lock sync with the output with motor speed adjustment, so they only have to buffer maybe 20-35mm of pickup travel worth of data, much less than a full revolution. You can't make the CD spin arbitrarily slowly, as a particular minimum rotation speed is required to balance the disc. Had they wanted to make use of fractional data rates, they would have potentially had to buffer a whole revolution worth of data, or at least more than half a revolution, i.e. about 200mm worth of pickup travel on the outside of the disc.
Leeki85 I think they wanted the simplest system possible to avoid confusion.
The original CD standard was designed to be possible to decode on very simple fixed function hardware. Adding half bitrate or half samplerate capability would've required ADC circuitry modified to handle it, a drive that could spin at half (or quarter) speed or enough RAM to build a decent buffer, logic to detect when a disc wanted half/quarter rate playback.
The original DVB spec isn't used for 4K/HDR, it's replaced by the incompatible DVB-S2/C2/T2.
It's easy to forget that the sub-$10 SOC embedded systems of today could match or even outperform a $1,000+ high-end home PC from 1980, when the original CD Audio standard was designed. It was certainly possible to make decoding hardware that would perform to those specs, but making something that would switch between differing formats, let alone in real time (variable rate), or performing relatively complex multiplications (for consumer hardware of the day) at a sufficient speed (ADPCM), would have put player production costs through the roof. So they settled on the best compromise of media size vs. playing time vs. general-purpose sound fidelity vs. playback unit construction cost.
A half-speed mono mode would have made sense, though.
Thanks to watching your previous work, my first guess was "double the play time? Just use mono tracks."
And I was right!
You're educational!
6:17 Badass Beethoven on the cover
This sounds like the tactic Sony's MiniDisc employed to expand its recording capacity, which they called "MDLP" (MiniDisc Long Play). They head 3 settings :
1. The regular capacity (aka SP) recording mode
2. MDLP 1 doubled the disc's original capacity (60mins = 120 ; 74mins = 154 ; 80mins = 160)
3. MDLP 2 quadrupled the disc's capacity (60mins = 240 ; 74mins = 308 ; 80mins = 320)
However, to achieve this, the sound quality was compromised, where the standard default mode was recorded at about 256kbps quality (which is pretty good) ; recording in MDLP 1 cut that in half (to 128kbps, which is the minimum MP3 quality you want without losing too much quality) in order to double the recording time ; and likewise with MDLP 2 where it was divided again so you got the crappy and tinny-sounding bit rate as low as 64kbps (96kbps is the absolute lowest you'd ever wanna go before your music turns to total crap).
The only useful mode was MDLP 1 so you could fit twice as much on a single MD, but still losing some sound quality.
The best solution was the Hi-MD which offered a much broader range of recording modes and sound quality. For me, I can get just under 8 hours of music on a single Hi-MD at a bitrate of 320kbps. That's enough music for a whole (working) day without having to change the disc, and that's assuming you play the whole program through uninterrupted. Consider you may stop or pause it now and then, it'll give you enough tunes for your whole day, including transit time or whatever.
Too bad the CD could not have a similar Hi-MD capability even if that meant it would only playback on special CD players, like the Hi-MD which of course needs to be played back on Hi-MD players only (regular MDs, even those recorded in MDLP 1 or MDLP 2 mode, is backward compatible with Hi-MD players).
I Got A Monty Python Record With Two sides on One Don't Know If You Have Ever Seen Or Herd Of It I Found It By Accident. Techmoan Rocks
Anthony Murphy a school friend told be about this in the late 80s. I’ve never known what it is - thanks
Matching Tie And HankerChief,2dexandsumplastik love the name .
That was a tricky thing by the Pythons. It had two completely different groves cut on each side, with different material recorded in each. I think it'd be a neat subject for its own video; I don't know if anyone else did it.
These are called "puzzle records" and they've been around as long as there have been disc records. Search TH-cam for "puzzle records" and you'll find several more, mostly from the 78 rpm era. One of the most common versions is a horse racing game, which typically has 6 interwoven tracks. You "bet" on which horse will win, then play the record to find out which horse won.
Kate Bush did this on her The Sensual World 12" single (www.discogs.com/Kate-Bush-The-Sensual-World/release/483472). Depending on where the stylus landed, you would hear either the vocal version or the instrumental version of the track.
High quality content presented in a highly skiled manner. That's why I like watching your videos even if the topic does not interest me that much! My girlfriend nearly said the same thing to me about your videos the other day.
We need MOAR MINUTES OF PLAYBACK. Oddware is being extended from LGR by Techmoan and great as normal!
I loved the trivia during the end credits! And thank you for the fantastic video, as always.
Love your humor. Cd stuck in amplifier...
Such a nice twist on an old joke/meme, brilliant. I like this editing style a lot. :)
Brilliance Audio (an audiobook publisher) used the same idea of dual mono channels in their Bookcassette system. Play sides A and B listenng to just the left channel, then play the tape again listening to just the right channel.
Before this, unabridged audiobooks on cassette would be prohibitively expensive, and were generally limited to the library market* or aimed at services for the visually impaired (RNIB, for instance). Brilliance also sold a headphone adapter so stereo Walkmans and the like could play these books - a stereo/mono switch, essentially.
Sometime later, Brilliance Audio actually championed an MP3-CD audiobook standard and sold a portable disc player with extra controls dedicated to navigating within the audiobook.
*The reason library editions of audiobooks are significantly more expensive than the retail versions is because they come with "insurance" - the library can order replacements for individual damaged tapes or discs without having to replace the whole book.
6:46 Good to know it has a meme collection.
I liked that little footnote bit during the Patreon credits; it's a nice touch that adds in a little bit of "extra information," even if it's not strictly about the topic of the video. I personally didn't know that the Beethoven's 9th story was an apocryphal one, nor was I aware that the symphony is actually shorter than a normal CD's lowest possible storage capacity.* Guess that shows just how much I know about CDs despite having gotten into the habit of collecting them in recent months. :P
*For those reading this who are unaware of the following, CDs can store up to 99 minutes of Redbook audio nowadays thanks to the same techniques that produced that abnormally long 1980's compilation LP. Of course, nobody outside of a select few CD-R manufacturers actually makes CDs of that length, given that there's only a very small minority of popular music albums/recordings that surpass 74 minutes.
Would you like to see my *dans la mēme* collection
I can´t remember ever heard of the cd version even as I am old enough. It fun to hear that the age of trying not that well thought out ideas.
Wow that CD was a really dumb idea lol
Seems pretty alright to me. It was mono audio in the first place, after all. And CD players were a hifi thing al those years ago, so left/right mono buttons etc were normal.
Agree, I'd be hard pressed to find any gear that has switches on it for one channel only playback.
I do have an old amp with a mono switch, but it just mixes both channels together to give you mono, it would not help at all with this CD. Good job CD's are on the way out, muti-hour Mp3's etc. are no problem these days.
Francis George mono SUCKS.
James Reeno no it does not
I'm just astonished that the audio CD specifications didn't have a standard Mono format. Just a quick flag at the start of the track that tells the player "yo this is in mono" and it could be played back accordingly.
Love your videos, very professional, laid back and detailed info too =)
The first thing I'd suggest to get double the time, would be to record on both sides. The second thing I'd say would be separate L and R. Up to 4x already without any clever stuff!
EDIT: these are my ideas before watching ;)
Yeah, why were there so few double sided CDs?
+Paul Sengupta Dual sided CDs actually violate the Redbook standard, which requires a CD to be 1.2 mm thick, with the polycarbonate layer being thicker than half of that (don't remember the exact thickness requirement). Making a two sided CD impossible within the standard.
Philips has even said that some DVD's which had a second side as a CD, couldn't use the CD logo on them, or that it would be copyright infringement.
I remember reading up on this a long time ago, as I was an electronics service technician.
Edit: Just found this info about the dual sided DVD/CDs
en.wikipedia.org/wiki/DualDisc
Look at it as a way of speed optimizing your listening experience. You can listen to the whole recording in half the time without altering the playback speed - revolutionary!