|
[ Home Page | Message Boards | News | Archive | Ask Cecil | Books | Buy Stuff | FAQs, etc. ]
A
Straight Dope Classic from Cecil's storehouse of human knowledge12-Mar-1976
Dear Cecil:
What with CDs this may be water under the bridge, but what was so special about the record
speeds 33, 45, and 78 RPM except that 33 plus 45 equals 78? How and why were these speeds
chosen? And why did 45s have that big hole? --John L., Dallas
Cecil replies:
Like so many things in this world, John, the various record speeds were determined by
chance and compromise. The compromise in this case was between playing time and fidelity.
The slower a record revolves, the longer it plays and the worse it sounds. Slow speeds are
acceptable for spoken-word recordings (many early "talking books" were recorded
at 16-2/3 RPM), but not for music, where sound quality is critical.
Thomas Edison's first phonographs were hand cranked, which made a single standard speed
virtually impossible. The listener cranked the machine at whatever speed "sounded
right," which usually worked out to around 80 RPM.
That was slow enough to get five minutes of material (then, as now, the average length of
a popular song) onto one of Edison's five-inch cylinders, and fast enough to provide what
passed in those days for decent fidelity.
When Emile Berliner invented the disc record in 1888, he designed it to meet the loose
standards of the Edison cylinder--five minutes of playing time at 70 to 80 RPM.
Formal standardization--at 78.26 RPM--didn't come until 1925, when the phonograph was
married to the electric motor. 78.26 happened to be the speed a common, mass-produced 3600
RPM motor would yield if fitted with an equally common 46:1 gear.
Around this same time the original acoustic method of recording was made obsolete by a
new, and far superior, electric system. The fidelity possible at 78 RPM could now be had
at a much slower speed--33-1/3.
But the record manufacturers felt that the fickle public--then deserting the phonograph in
favor of a newer novelty, the radio--would be put off by the cost of converting from 78 to
33-1/3. So, through the twenties and thirties, the process was used only in studios and
radio stations.
In 1931, RCA Victor badly bungled an attempt to put a cheap, imperfect 33-1/3 system on
the mass market, and no one tried it again until 1948, when Columbia Records introduced
Dr. Peter Goldmark's new "microgroove" system.
Columbia shrewdly pitched the new "LPs" to classical musical collectors,
pointing out that the longhair listener could now settle back and enjoy an entire movement
of a symphony without the annoyance of changing the disc every five minutes.
Hoping to set 33-1/3 as the new standard, Columbia offered the process free to any company
that cared to use it.
But RCA Victor, still licking its corporate wounds after the 1931 debacle, would have none
of it. The company insisted on making what looked like another bonehead move: dumping an
entirely new system--45 RPM--on the market.
Just as Emile Berliner had adapted his disc to meet the standard of the Edison cylinder,
RCA had designed the 45 to conform to the 78--it offered the same playing time, somewhat
improved fidelity, and the dubious advantage of being more "convenient" because
the discs were smaller.
In presenting the 45, RCA unloaded some drivel about how 45 RPM was the optimum speed for
sound reproduction. But it was revealed that in fact RCA had told its engineers to come up
with any old speed so long as it wasn't compatible with Columbia's system.
The big hole was apparently supposed to make the two types of records even more
incompatible.
Thus began the so-called "war of the speeds." Since 45s offered few real
advantages over the old 78s, most of the smaller manufacturers opted for the Columbia
system.
RCA, though, held out for 18 months, during which time industry sales volume dropped 25
percent as consumers waited for the giants to fight it out between themselves.
Finally, in 1950, RCA capitulated--sort of. It began making 33-1/3 records using the
Columbia system.
But it didn't discontinue the 45. Instead, it spent $5 million advertising 45 RPM as the
preferred speed for popular music.
In reality, of course, the speed didn't make any difference. A 7-inch record was simply
more convenient for single tunes than a 12-inch one.
Nonetheless, the public allowed itself to be duped, and in 1951 Columbia began making 45s
too. Thus we ended with one speed and spindle size for popular songs, and another for
symphonies. The 78, mercifully, was out of the picture by 1950.
Actually, the whole concept of constant turntable speed had been obsolete since the turn
of the century. At a constant turntable speed, the velocity of the grooves moving past the
stylus decreases as the record plays--the inner spirals of the track being, of course,
much smaller than the outer ones, circumference-wise.
If the groove speed were held constant instead of the turntable speed (in much the same
way that a reel of film plays out at a steady 24 frames a second), it would be possible to
record over 90 minutes of material on a single side. You'd have greater fidelity and a
lessened potential for damage to the record.
A few phonographs designed on this principal were marketed in the early 1900s.
But technology is one thing and show biz is another. For obvious commercial reasons--just
imagine how much more crap Barry White would need to pad out an album--this line of
development was never pursued.
--CECIL ADAMS
The Straight Dope / Questions or
comments for Cecil Adams to: cecil@chicagoreader.com
Comments regarding this website to: webmaster@straightdope.com
Copyright © 1996-2004 Chicago Reader, Inc. All rights reserved.
No material contained in this site may be republished or reposted without express written
permission.
The Straight Dope is a registered trademark of Chicago Reader, Inc.