UPDATE - 11/8@7:26AM: Rush sound engineer Richard Chycki posted an update to his blog yesterday where he talks a little about the reissue:
... Like the other Rush surround releases to date - Moving Pictures, A Farewell To Kings, Fly By Night, and Signals - 2112 has been remixed at a 96 khz 24 bit high resolution from the original multitrack masters in a 're-creation' direction taking advantage of the 3-dimensional soundscape of surround, rather than a complete re-interpretation of the mix. I have had quite a few questions about the technical side of the process so time depending, I'll try to get an article put together about it and get it posted here or published. ...
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A couple of weeks ago we learned that Mercury Records will reissue a Super Deluxe version of Rush's classic 2112 album this coming December 18th. No further details were given at the time, but a tweet from Rush sound engineer Rich Chycki shortly after the announcement confirmed that it would include a 5.1 surround sound remix of the album. Amazon.com is now listing 3 different versions of the 2112 Deluxe Edition for pre-order: a CD plus Audio DVD Deluxe Edition, a CD plus Audio Blu-ray Deluxe Edition and a CD plus Audio Blu-ray Super Deluxe Edition (thanks Gis Bun). The difference between the DVD and Blu-ray versions seems apparent; one includes a DVD disc and the other a Blu-ray disc. But there's no indication of what's included in the Super Deluxe Edition, although it costs over $20 more than the standard Deluxe Editions. More information as we learn it. 2112 was included as part of the Sector 1 box set release last year, but no 5.1 release of the album was included.