1 press ff (fast forward) for 1x fast forward, 2 press ff again for 2x fast forward, 3 press ff again for 4x fast forward – Sonic Blue 4500 User Manual

Page 35: 4 press ff again for 16x fast forward, 5 press ff again for 20x fast forward, Using multispeed slow motion, 1 press play for 1x slow motion, 2 press ff for 2x slow motion, 3 press ff again for 3x slow motion, 1 press play to playback at normal speed