figmo@tymix.UUCP (Lynn Gold) (10/03/84)
78: Given the technology at the time, the best fidelity they could get
and still be practical was 78. Radio broadcasts were often recorded
on 16" transcription disks at this speed. Because the sound quality
was so much better on the outside of the disk than on the inside, the
first disk would go from the outside to the inside, the second from the
inside to the outside, etc., until the program was finished, so it would
not be as obvious when they switched records (you wouldn't hear a sudden
change in the sound quality of the broadcast).
45: These were designed to be portable. The reason for the wide hole in
the middle has something to do with physics and acoustics, if I'm not
mistaken.
33: These were designed to be able to hold more music at a reasonably
tolerable rate (in terms of sound quality). 33s do lose in many ways
compared to the old 78s (you lose a lot of highs).
--Lynn