#Multi-speed
He probably means when the head is reading from the inside track
(sector zero), that the disc spins at 530 rpms and 200 rpms when the
head is at the outer most track.
In any case. All CD-ROM drives read data off the disc while the bits
pass under the head at a constant speed. This requires the drive to
decrease the disc's rotational speen as the head moves from the
inside tracks to the outside tracks.
Double speed and quad-speed drives are those which spin the discs at
double or quadruple the speed of normal drives. This leads to an
increased data transfer rate as far as we're concerned.