5.1 Channel Surround (70 mm 6-Track) (analog magnetic)

Delivers six audio channels from a 6 channel source:
Four channels for speakers at the front-left (L), left center (LC), right center (RC), and right (R).
One channel for speaker at the center-center (C)
One channel for surround speaker at the rear-monaural surround (S)

5.1 Channel Surround (3-2 Stereo) (analog magnetic: Dolby Stereo "Baby Boom")
Delivers five audio channels and 1 LFE channel from a 6 channel source:
Two channels for speakers at the front—left (L) and right (R).
One channel for speaker at the center—center (C).
Two channels for surround speakers at the rear—surround left (LS) and surround right (RS).
One low-frequency effects channel (LFE).