Basically, as I understand it, a near-field mix is a remix of the theatrical audio for home theater. Near field because you’re near the speakers in a home theater, and in a far-field mix (i.e. a commercial theater) you aren’t. So, the Laserdisc audio is redone to sound better in a home, whereas the original optical track sounds better in a movie theater.
Maybe I am missing something here, but thanks to RU.08 I had the chance to listen to the “optical track” in comparison now and to my eyes and ears, the LD audio is technically better in every aspect.
Not that the optical track wouldn’t be worth being preserved due to the different sound and historical value alone of course, but the LD audio features a significantly higher dynamic range (just like DiscLord reported it) and is also “clean” whereas the (I assume analog) optical track has distortions which are especially noticeable during the dialog.
Thus I’d rather assume that it was in fact the LD audio which was originally created as the cinema master back then and not vice-versa. If they would have adjusted it to sound “good” on home theaters afterwards, normally that would have meant a reduction of dynamic range, not an increase as many nowadays low-end soundbar stuff (or worse) actually sound better with higher compressed sources. And given that it the mass market, no surprises here. However, the LaserDisc would predate that loudness-war era anyway so I wonder where the “near-field mix theory” comes from.
At least from what I’ve heard now, the optical track sounds like a decent attempt to reproduce the original master, however with all the limitations of these analog optical systems that time whereas the LD gives you the raw, dynamic deal.