About the Skywave X70's sound output with upmixing disabled
When xupmix is disabled, the sound output varies depending on the signal type:
Dolby Atmos content: Because the signal inherently supports multiple channels (front, surround, and overhead speakers), disabling xupmix does not affect the original immersive output; sound will still be played omnidirectionally.
Non-Dolby signals (such as stereo or standard 5.1): xupmix simulates a vertical sound field (surround + overhead) for these signals. When disabled, the system will play back the original channel layout—for example, stereo content will primarily be output through the left and right channels of the front speakers, with no input from the surround and overhead speakers, resulting in a more focused sound in the front area.