Mike Oldfield surround mixes

Mike Oldfield has released a lot of his wonderful albums in surround sound! (Like other artists who respect their own music should do too!)
On DVD with surround mix by Oldfield are released:
Tubular Bells, Tubular Bells 2000, Hergest Ridge, Ommadawn, Incantations (extract), Five Miles Out, Crises, Discovery & The Lake (extract), Return To Ommadawn.

Besides that, the boxset ‘Boxed’ and the live album ‘Exposed’ was SQ surround encoded. That is also written on the cover. If you have a surround receiver with surround speakers that can decode these 2 albums sounds nice. Some instruments are most present in the rears.

The mystery

Other albums also seems to be surround encoded. That is albums like Platinum (1979), Heavens Open (1991) and Man On The Rocks (2014) where a lot of stuff appear in the rear speakers, when decoded through a ProLogicII decoder to 4 channels. But if the album QE2 get the same treatment then there is nothing speciel happens in the rear channels. Why is that?

Why are some of Oldfield’s albums seemingly surround encoded without it is mentioned everywhere?

If you have any clue please comment on Twitter, Facebook or Quadraphonicquad forum

Here is an example:

Mike Oldfield – Music From The Balcony (extract from Heavens Open 1991)

– ProLogicII Decoded

mp4 (with quad sound as 5.1 with muted center and sub)

Quad flac:

Full overview of ‘Music From The Balcony’:

Very clear that there is a big difference between front and rear channels