Vibrations -First song on CDs

Every new CD technology claim that their discs provide the best listening experience. I have used iPhone4 to measure the vibration of the CD player while playing the first song of the disc (songs are read from innermost to outermost part of the disc).

Settings of the iOS app Seismometer (v2.1):

Sampling rate: 120Hz

X, Y, Z-axis: ON

Filter: Bessel

(Musical Fidelity X-PSU DC power supply was placed on the 防滑墊)

The results show that SACD and SHM-CD spin more stable than the ordinary CDs.

While ordinary CDs vibrate in both Y- and Z-direction (SHM-CD performs well in the Z-direction), SACD mainly vibrates in the Z-direction.