a_purist said:
For this preservation, what would be more accurate? 2.0 or 1.0? In principle, both. But not for a film before… what year? I don’t know how you see it.
The two channels of the “dual mono” soundtrack are exactly the same, and the sound was intended to be reproduced by a single loudspeaker behind the screen at the center.
In a 2.0 setup, both 2.0 mono and 1.0 tracks would be reproduced the same way, i.e., the same signal coming from both loudspeaker. The impression would be that of a single phantom channel at the center. In a setup with three front channels (e.g., 5.1), 2.0 mono would be reproduced from L and R, while 1.0 from the center. So I believe the latter would recreate more faithfully the theatrical experience.