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This topic comprises 3 pages: 1 2 3
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Topic: LP maximum playing time
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Monte L Fullmer
Film God
Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004
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posted 04-08-2006 02:44 AM
quote: Bill Enos
How were rotation speeds--16, 33 1/3, 45, 78 arrived at?
It was Emil Berliner, the inventor of the gramophone, By using points which could be made from steel sewing needles and pins, the size of the stylus effectively determined the size of the grooves in a record and the recordable frequency range limited by this groove size determined a speed between 70 and 90 rpm.
When Edison came out with their 1/4inch thick, 10 inch platters before WW-1 and afterwards, these were recorded at 80RPM.
Standardization did not begin until 1912, when the British Gramophone Company conducted listening tests on their back catalogue. They settled on the average (or possibly the median) of these tests, which turned out to be 78 rpm. American recording factories then adopted this speed standard after the demise of the Edison record..
Records of 33 1/3 rpm were developed in conjunction with films. A 12-inch 78 with Berliner-type (thick) grooves could hold between 4 and 5 minutes per side. The first practical sound films produced in the US in the late 1920s had their sound on separate disc records and it was more important for the sound to be continuous. A reel of film might run for 11 minutes, so a rotational speed of about 32 rpm was required to make the sound match the picture.
History doesn't tell us why precisely 33 1/3 was chosen.
It seems CBS engineers (who developed the first LPs in 1948), simply experimented with one of the old machines hanging around in their workshop. They then developed new groove dimensions which gave an acceptable signal-to-noise ratio with the new plastic material Polyvinyl Chloride, PVC, or just plain "vinyl".
The 45 rpm speed was the only one to be decided by a precise optimization procedure (by RCA Victor in 1948). Calculus was used to show that the optimum use of a disc record of constant rotational speed occurs when the innermost recorded diameter is half the outermost recorded diameter. That's why a 7-inch single has a label 3 1/2 inches in diameter. Given the CBS vinyl groove dimensions and certain assumptions about the bandwidth and tolerable distortion, a speed of 45 rpm comes out of the formula.
Also, since Columbia intruduced the "LP" in 1948, RCA wasn't going to be outdone by Columbia, thus invented the "45" to attract attention to their new compact turntables - a definite marketing ploy, which did work for only two years, until 1950 when RCA finally succumbed to the demand of the LP and started to issue LP's themselves.
But, the "45" stayed with us as the 'single' being of the right speed to hold the fidelity and the right size for compactness to make it a separate indentity by itself.
Also, a buzz of word in the halls of RCA on that rotation speed was that 78 minus 45 equals 33 - to render another slap at Columbia .. And, what is interesting is that Columbia NEVER had placed a patent on the speed - they left for an open market for the usage of the speed to the other labels, including RCA-in which they were invited in on this introduction, but David Sarnoff, head of Victor division of RCA flatly refused.
Only thing that Columbia did lock up in the patent office were the initals "LP". Thus, other labels had to use the generic phrase - "Long Play".
Then, for the 16-2/3rpm was simply the LP cut in half for dictaion purposes since the full frequency range was very limited to frequencies in the human voice range - to get an hour of recording on one side of the vinyl
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Mike Babb
Master Film Handler
Posts: 250
From: Norwich UK
Registered: Jul 2002
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posted 04-08-2006 11:18 AM
http://www.urpressing.com/tips.html
PRODUCING GREAT SOUNDING PHONOGRAPH RECORDS
or, Why Records Don't Always Sound Like the Master Tape
BY: KEVIN GRAY 5/3/97
The phonograph record is a marvelous medium for storing and reproducing sound. With frequency response from 7 Hz to 25kHz and over 75 dB dynamic range possible, it is capable of startling realism. Its ability to convey a sense of space, that is width and depth of sound stage, with a degree of openness and airiness, is unrivaled by anything but the most esoteric digital systems.
That having been said, it is important to understand the limitations of this medium in order to make great sounding records. The first limitation is recording time and level (volume). The amount of time possible on a record side is entirely dependent on the cutting level (volume) and the amount of low frequency information (bass). Bass uses more space than treble.
The record groove is an analog of a sound wave. Try to picture looking down on a narrow river or stream. The left bank is the left channel and the right bank is the right channel. Your turntable's stylus is a wide round raft that is going to travel that river. For simplicity, imagine that the banks stay parallel, (left and right the same) which means the sound is monaural. The louder the sound and or the heavier the bass, the wider the whole river (and your boat) wiggles side to side. The higher the pitch (frequency), the closer together the wiggles get. In other words the sharper the twists and turns, the higher the pitch. Obviously, everything from bass to treble is happening at once, so the gently sweeping wide curves (bass guitar and bass drum) have smaller, more jagged wiggles (vocals, guitars, keyboards, cymbals, percussion, etc.) superimposed on them. It should be mentioned here that if the bass information is too loud, your raft gets thrown over the embankment (skips). So now you should be able to see that the louder the music is cut, the wider the groove wiggles, and the less time can fit on the side. Or looking at it the other way around, the longer the side, the less room for wiggles (volume and bass).
Next limitation: treble. You can put as much treble on a DAT or CD as you want. Unfortunately this is not true on a record (or analog tape for that matter). Although 25kHz response is possible, excessive transients are a problem. There are several reasons for this. It was decided with the advent of the first electrical transcription phonograph record, to reduce bass and boost treble in the cutting of the master record. This reduces bass wiggles and makes treble louder. And we aren't talking about a little bit of cut and boost here, we're talking about a 40 dB change from bottom to top! Without the bass cut, you'd only have about 5 minutes on your LP side. Without the treble boost, you would hear mostly surface noise. You don't have to worry about this drastic cut and boost sounding funny, because the phono preamplifier in your amplifier or receiver has an inverse curve which boosts the bass and reduces the treble by the same amounts used in cutting, so the whole process comes out linear. This was standardized worldwide in 1953 and is called the RIAA record and reproduce curves.
I said you don't have to worry about the RIAA curve, but the cutting engineer sure does! Power amplifiers (100 to 400 plus watts) are used to drive the tiny coils (one for each channel) in the cutting head. They're like miniature speakers which instead of just moving air, push the stylus that etches the groove in your record. With 20 dB of treble boost, you can only imagine the beating that the cutting head takes from cymbal crashes and the like. The coils are helium cooled but still can reach 200 degrees Centigrade. A circuit breaker is used to prevent catastrophic destruction. This doesn't all add up to the limitation it seems, because it is still possible to cut levels higher than can be played back.
Let's take a look at cymbals and vocal sibilance (those loud 'S' sounds). "Why", do you ask, "Do they sound OK on the tape but sometimes so awful on the record?" The answer is twofold. First, the problem is aggravated by the high frequency boost we just discussed. Further excessive boost in your mix makes it that much worse. Unlike a cymbal crash, in which the impulse is short (the actual hit of the stick on the cymbal), the duration of an 'S' is considerably longer, so it is even more pronounced. And second, the worst part: Remember the river? Suppose the river's twists and turns are actually tighter than your raft? Ever watch a raft attempting rapids? Well, that is exactly what your stylus is doing when it hits a loud cymbal crash or a loud 'S' in the record groove. At the instant that the curvature of the groove is tighter than the tip radius of your stylus (raft), it goes over instead of through 'the rapids,' and you have 100 percent distortion. The higher the frequency and or level, the greater the curvature and distortion.
The cutting engineer can usually tell if treble peaks are going to 'break up' on playback by the amount of current drawn by the cutting amplifier. This is measured by current meters on the amplifiers. If the current is excessive, the only way to prevent this is to use a very fast-attack treble limiter to reduce the intensity, and therefore, the groove curvature.
While we're on the curvature subject, it is necessary to explain one more thing. Ever wonder why outside diameter cuts on a record sound clearer and cleaner than inside ones? Unfortunately it's a fact. Why? The answer is geometry and curvature again. One turntable revolution at 33 1/3 rpm on an LP takes 1.8 seconds. That 1.8 seconds is spread over a circumference of 36 inches on the outside of the record. At the minimum allowable inside diameter that same 1.8 second revolution would only cover 14.9 inches. You can see from this, that a gentle wiggle spread over 36 inches would get quite 'scrunched' over 14.9 inches. A jagged groove at 36 inches would get really scrunched at 14.9 inches (remember the rapids). Excessive treble can even cause the cutting stylus to accelerate so fast that its back edge wipes out what the front edge just cut! It's unfortunate, but treble rolls off, and distortion goes up as you approach the center of the record. It is quite gradual, but if you compare the source recording to the disc, this actually starts to become noticeable after the second cut or so. Any attempt to compensate for this by boosting the treble, only makes the problem worse (greater curvature remember).
I'll discuss stereo very briefly. If the sides of the river don't stay parallel, it's stereo. In other words, any difference between the two channels causes the stylus to move up and down in addition to sideways. As the stylus digs deeper, it is using more precious disc space. The moral for engineers is: If you are looking for hot levels or long sides, don't pan instruments like drums and percussion hard left and right. Keep the bass and bass drum in the center, and keep everything in phase. An out of phase snare or bass drum can wreak havoc. Use an oscilloscope if possible!
All else being equal (bass, volume and depth of cut), by allowing the end of the record to finish farther out from the label, instead of spreading the grooves farther apart to fill all the space, will actually make the record sound better. However, I understand the concept of making the record look 'full.'
So much for the primer on record cutting. Now let me give you some additional tips on making your record sound great. First, keep it as short as possible. I know this isn't always possible, but particularly if hot levels are important, keep it short! How short? As a general rule, an LP should be under 20 minutes and 24 minutes maximum. 16 to 18 minutes is ideal. Also, try to balance the side times, preferably within one minute. If one side has to be longer, put more of the quiet material on that side. This will insure even levels. If the sides are long, remember that the more bass, the lower the cutting level (volume). It is possible to squeeze 30 minutes on a side but the level will be so low you'll have to crank it just to hear it, and you will hear the surface noise!
A hot club record should be under 12 minutes, 9 to 10 minutes is ideal. Some of the top club DJs tell me they won't even play records that are over 12 minutes long because they know the levels will be low and don't want to adjust gain.
Watch excessive treble boost in the 8 to 16 kHz range in mixing. You won't get it back on your record. You can't break the laws of physics, sorry. A good idea is to check your mix against a record you like with lots of cymbals. If you hear a lot more sizzle on your tape, chances are it won't make it to the record. Particularly watch those 'S's. Use a de'esser on vocals. I don't do endorsements, but DBX makes a great one. This will give you more overall treble because in cutting your record, the treble limiter won't be chomping on your cymbals too.
Put your hottest, brightest, most dynamic mixes on the beginning of the disc and they'll stay that way. If possible keep the quieter material on the inside tracks.
A word about comparing DATs and CDs to a record: digital levels do not bear any relationship to analog levels. We're talking apples and oranges here. The analog output level of a CD player or DAT deck can be anything the manufacturer wants it to be, but it is generally higher than a phono preamp output. There are two reasons for this. First the digital equipment manufacturers want CDs and DATs to sound better (translate Louder) than records. If the DAT or CD is fairly wide dynamic range, a record can be as loud. HOWEVER, there has been a trend in the last few years to compress digital tapes almost to the point of the level display not moving from the beginning to the end of the song (second reason). This started with rap, filtered through to dance and club mixes, and finally to most new commercial pop releases. The result is that what used to be the peak level is now the average level and we're talking 6 to 8 dB louder than is physically possible to put on a phonograph record (or analog tape). Remember that the groove can only move so far before the playback stylus mistracks or skips, and magnetic tape can only be driven so hard before it saturates. At any level, a digital recorder is only printing ones and zeros. There is no digital counterpart. The bottom line is that a really compressed CD or DAT is going to be 6 to 8 dB louder than your record. This is not a defect, it's a FACT OF LIFE. I prefer to think of the digital compression as a defect and a scourge to anyone who appreciates dynamic range, but now I'm editorializing.
If the levels are not matched in one of these comparisons, the compressed digital source (6 to 8 dB louder) will sound like it's got more of everything. I've heard the record described as sounding like it's under water. If the levels are matched, suddenly they sound almost identical. If you are trying to accurately compare a record with a digital source, use a mixer or preamp to raise the level of the record or lower the level of the DAT until they sound very similar and then compare.
While I'm getting things off my chest, how about making the cutting engineer's job easier. Analog tapes are easily timed when rewinding, and have visual clues such as leaders and splices. DATs and CDRs do not. When supplying DAT tapes or CDRs for record lacquer mastering, always provide three things, please! One: Start IDs for each song, not just each side. Sometimes it's hard to tell where one song ends and another starts. Also, they're handy for checking each song. Two: Note accurate timings for each song AND total side time including pauses. This is particularly important if your DAT deck doesn't print absolute time on the tape. So much time is wasted by the cutting engineer having to figure out times and it's imperative to know before cutting. Three: Any level or EQ (tonal) changes you want made. One thing to be aware of is that just because all the songs peak at zero doesn't mean they will all be at the same apparent volume. This is also true with analog tapes, but to a much lesser degree (remember the digital level tutorial). This is where good old VU meters (with 6 dB pads) come in handy when you are assembling your DAT or CDR.
I hope you find these tips and suggestions helpful, and apply them. You may have guessed from this, that records were not originally intended to store the kind of energy today's music contains. It's true, but if you mix with the limitations in mind, it will make a huge difference in the final product. It's unfortunate, but the approximately 10 year lull in the production of phonograph records, from the mid 80's to mid 90's, caused a lot of engineers to forget these limitations. In the meantime, a whole new generation of engineers has come along who never dealt with record production before. This is for you! Make some great sounding vinyl!
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Monte L Fullmer
Film God
Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004
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posted 04-08-2006 03:25 PM
quote: Leo Enticknap
I didn't know that turntable design was part of the issue as well.
..oh Yes, when Columbia, in 1948 introduced the LP to the public, Sarnoff, head of RCA, about had a coronary on this since he hated Paley, of Columbia, so bad. Yet, Paley was very opened minded to wanting Sarnoff to be a part of this new concept since Paley didn't want to lock up the format in a patent - Paley wanted to keep it an open market.
Why Sarnoff hated Columbia is that Columbia really had the classical artists on their label: Ormandy with the Phila, (who left RCA for Columbia back in 1943, which really hurt RCA in their classical department), became their biggest draw, then came Bruno Walter with NY, and they had Reiner at the Pittsburg (who later fell out of favor with Columbia and went to RCA..to rescue Victor due to Toscanini's mentioning of retiring from the NBC.)..to name a few. RCA had their big draws with, Toscanini, Koussevitsky at the Boston, Fiedler, Rubinstein, Horowitz, but the others artists where forgettable.
Thus,when Columbia shot out with the LP..the '78' recordings suddenly became the LP versions..Victor and Sarnoff decided not to follow along (Sarnoff HAD to always be the front runner of everything...including the TV thing...but hit a horrible snag with Farnsworth since Farnsworth didn't want to sell his patent, thus the court ordered Sarnoff to pay royalities to Farnsworth..which really put a horrible know in Sarnoff's shorts REAL BAD..), thus to be 'original' - shot out with their "LP" version of the 45rpm, 7inch disk -with the big hole - anything to be different from Columbia and try to sell this to the public.
Yes, the red vinyl "45" sets were very unique in themselves, but, record changes were still bein done. Thus, the same old concept of interrupted music was still apparent as with the 78rpm sets.
With Columbia's more superior 12 inch, 20 plus minute uninterrupted playback won the vinyl wars with the public, and Victor with Sarnoff, to stay alive in the recording business, HAD no choice but to accept the LP standard, thus in 1950 started to release LP copies of their 78 catalogs (being the first LP release, the LM-1, on a 10inch vinyl with Fiedler).
Quite the 'vinyl wars' back then.
I do have some 16-2/3rpm, 7inch recordings..I record these to the computer from a normal turntable and take a recording program, and on playback, slow the playback down in half
and then resave the results.
-Monte
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Bernard Tonks
Jedi Master Film Handler
Posts: 619
From: Cranleigh, Surrey, England
Registered: Apr 2001
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posted 04-08-2006 04:16 PM
There are 16-2/3 rpm 10” discs for sale on Ebay.
New & used 16 Rpm. Check out the deals now!
http://www.ebay.com
Description
Item Specifics - Music: Records
Speed: 16 RPM Genre: Religious
Record Size: 10" Sub-Genre: Christian
Duration: EP
I am offering for bid 68 American Bible Society "The Talking Bible" records, 16 2/3 RPM. 1 side on all records has an American Bible Society blue label and on the other side the label is in braille.
They are the King James version read by Alexander Scourby. Some of the titles are Genesis, Revelation, 1 & 2 Chronicles, Lamentations & Ezekiel, Psalms, Jeremiah, Acts, St. John, Ruth, Isaiah, Daniel, Joshua, St. Luke, St. Matthew, St. Mark and many more.
There is also a green label album, Instructions For Talking Book Users, 1 side 33 1/3 the other 16 2/3. The records are all in good condition.
All in paper stock sleeves. A few of the sleeves have writing on them. The records were produced for the American Foundation for the blind. Any questions, please contact me. Thanks for looking.
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Michael Schaffer
"Where is the
Boardwalk Hotel?"
Posts: 4143
From: Boston, MA
Registered: Apr 2002
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posted 04-10-2006 06:15 AM
quote: Dr Leo
I have one recording of Beethoven's 9th crammed onto a single LP: movements 1,2 and about 5 minutes of movement 3 are on side 1 (around 33 minutes I'd guess) with the rest on side 2. Because the disc is cut so close to the label rim, it needs an extra half a gram of tracking force to stop the needle jumping during the last 5 minutes or so of each side. The signal level is really low, too, and that record really doesn't do the performance justice. Interestingly, this is a Deutsche Grammophon LP and they're not known for cutting corners on technical quality. It was one of the last LPs they produced (1989), and by that time most serious classical music buffs had probably gone to CD. If the recording hadn't been made to commemorate the fall of the Berlin Wall, I doubt if they'd have released an LP version at all.
Probably this one:
I actually remember the splitting of the third movement was quite common, including in DG releases, although it may have been more common for mid-price and budget releases of older recordings than for full-price releases of new recordings. The 9th symphony was often released as a 2-LP set with one of the shorter symphonies, typically the 8th, on side 1, then the first two movements of the 9th on side 2, the third on side 3, the 4th on side 2. But even then, the ending never sounded really good because it features the full choir and orchestra more than 25 minutes into the disc.
I also remember how some longer pieces without break, for instance Strauss' "Eine Alpensinfonie" (45-50 minutes), had to be split somewhere in the middle. Particularly difficult since right in the middle, there is a very long continuous section called "On the Summit" which is the musical climax of the piece, and that's where it was usually split. So side 1 ended on a massive orchestral chord which is supposed to be the moment the music develops to, and that chord also leads directly to a long section which elaborates on that musical moment. Except on the LP, it didn't. What followed was some light crackling and the very unclimactic sound of the stylus being lifted from the groove. Then you had to get up, turn the LP, restart it, and the same chord would begin side 2. That really sucked. Plus the really quiet beginning and ending was always spoilt by some crackling, no matter how clean you kept the LP. I don't have any nostalgic memories of that.
quote: Mike Babb
With frequency response from 7 Hz to 25kHz and over 75 dB dynamic range possible, it is capable of startling realism. Its ability to convey a sense of space, that is width and depth of sound stage, with a degree of openness and airiness, is unrivaled by anything but the most esoteric digital systems.
I would say "up to 25kHz" is *extremely* theoretical. In reality, there is so much distortion above 12kHz or so that it really doesn't matter how high the frequency response theoretically goes, apart from the fact that most people don't hear much if anything above 14kHz or so. And it gets worse towards the middle with slower groove speeds. It is that diffuseness of the higher frequencies that a lot of people perceive as "warmth". Even taking into account the alteration of the waveform (which is distortion too) introduced by quantization, a digital medium such as CD is much closer to the original sound. Plus the channels separation is so much better on digital systems - and it's mostly that which defines the width of the sound stage and the placement of sounds therein. I recently had the opportunity at a friend's house to listen to some LPs again on a good system after a long time in which I had heard virtually none, and compare them to CD releases of the same recordings, mostly orchestral, and I am still wondering why so many people still mythify the LP medium so much. A properly mastered CD sounds so much more like the original, not to speak of the much lower noise levels which in orchestral recordings is very important too (because there are many very quiet passages).
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Leo Enticknap
Film God
Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 04-10-2006 03:51 PM
Yes, that's the LP I was talking about.
A similar example to your Alpensinfonie only worse is an earlier recording of Beethoven 9 I have: a 1928 one (Vienna PO/Weingartner) on 8 78s (16 sides). In some cases a quite substantial phrase is repeated across both sides, making it impossible to seamlessly edit some of the side breaks when transferring it to CD. I've also got a 78 set of the premiere recording of Walton 1, which totally destroys what should be some amazingly climactic moments with side breaks. Given that each wax original had to be cut in one continuous take, the conductors and producers of large-scale orchestral works on 78 must have had to think quite carefully about where the side breaks went, I'd have thought.
quote: Michael Schaffer
I am still wondering why so many people still mythify the LP medium so much. A properly mastered CD sounds so much more like the original, not to speak of the much lower noise levels which in orchestral recordings is very important too (because there are many very quiet passages).
Possibly because many CDs are not properly mastered, whereas a higher proportion of LPs seem to have been produced with greater attention to technical quality. And although, admittedly, this isn't a sound quality issue, the packaging and presentation of most CDs is cheap and cacky.
Even a good IB surviving print from the '30s won't look as sharp and as saturated as an Eastmancolor print made from a state-of-the-art recombination of the seps; yet I know people who think nothing of travelling hundreds of miles for the chance to see one projected.
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Michael Schaffer
"Where is the
Boardwalk Hotel?"
Posts: 4143
From: Boston, MA
Registered: Apr 2002
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posted 04-10-2006 05:41 PM
quote: Leo Enticknap
Given that each wax original had to be cut in one continuous take, the conductors and producers of large-scale orchestral works on 78 must have had to think quite carefully about where the side breaks went, I'd have thought.
Indeed they had to. In those days, recording sessions, especially of longer, continuos pieces had to be extremely well planned and it often took them several days to finish a complete recording. It must have been an incredible relief when tape came into use. Richard Osborne's biography "Herbert von Karajan - A Life in Music" contains a lot of interesting details about how the recording process in the studio evolved from these days to the digital era (which Karajan also pushed massively).
quote: Leo Enticknap
Possibly because many CDs are not properly mastered, whereas a higher proportion of LPs seem to have been produced with greater attention to technical quality. And although, admittedly, this isn't a sound quality issue, the packaging and presentation of most CDs is cheap and cacky.
Even a good IB surviving print from the '30s won't look as sharp and as saturated as an Eastmancolor print made from a state-of-the-art recombination of the seps; yet I know people who think nothing of travelling hundreds of miles for the chance to see one projected.
Indeed, a lot of CD releases in the 80s and also later were simply not mastered very well for the new format and its porperties. Making a good recording is still a difficult and mysterious art which few really master (pun intended). But if you get a well recorded and mastered CD, the sound is vastly superior to anything you could ever hope to achieve with an LP.
There is nothing wrong with nostalgia. I am also interested in "retro" technologies, and yes, in some cases, these were actually better than current stuff. In any case, they are part of our cultural history. But I am often puzzled by how some people perpetuate sheer myths about them.
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