Chapters 8-9. From about halfway point of Chapter 8, the film readies the audience for its climax. No more slow down. Go, go, go. This sections again brings in some oxygen environments so more traditional sound effects elements whip around the room, enhanced by the fact that, in space, when people move through structures, it looks like they're flying. Turn these chapters up all the way, neighbors be damned!
Admittedly, the differences between the discrete 7.1 and 5.1 are not vast -- it's not as revelatory as jumping from 5.1 to Atmos. However, once you go discrete, you never go back. The original Blu-ray's 5.1 mix sounds very good, but it was always missing something. Simply by adding the two extra rear channels, 'Gravity' is so much more immersive. We gain very specific placement of voices, musical score, and panning sound effects as they wrap around you. Given the film's quieter, less aggressive moments, sometimes the two tracks sound similar. But move into the action, with space debris colliding, the camera swirling, characters weightlessly flying inside and outside of space crafts, you are immediately pulled toward the screen. Sound effect panning becomes seamless and enveloping. The two best sequences are Dr. Stone inside the ISS, and the rousing climax [SPOILER ALERT] as the Tiagong's falls to Earth culminating as the parachute opens and the capsule plunges into water. [END SPOILER]. 2b1af7f3a8