I wanted to listen to my 4 channel 24/96 TASCAM DR-680 recordings on disc, and since I have an old Pioneer DVD player that plays DVD-A, I thought I'd go that route.
I also wanted a method that didn't require a lot of fiddling around or expensive software.
There were two programs used: Audacity and BURN.
I imported my 4 track recording into Audacity as two stereo tracks (#1 - piano, #2 - cello). Then I split each of those stereo tracks so I had 4 separate tracks:
piano: left channel and right channel, and cello: left channel and right channel.
When exporting them from Audacity using "Custom Mix" [changed in Preferences], I mapped them as follows:
piano left ch>Channel 1, piano right ch>Channel 2, cello left ch>Channel 3, cello right ch>Channel 4.
I then burned the resultant .wav file in BURN using the "DVD-AUDIO" setting and it played back with the piano on the front speakers and the cello on the rear ones.
The DVD player showed the file as PCM 24/96.