Not easily, and not directly. All analog inputs on Sonos have a minimum of a 75ms buffer delay, which is used to both transfer from analog to digital, and ensure the content will play in sync across all Sonos speakers.
Digital inputs on the Sonos sound bars are much lower in latency, but that is only for the “room” that the sound bar and it’s satellites are in. As soon as you group other rooms, you have to pay that minimum of 75ms latency, as isn’t is in the design of the Sonos system.
Additionally, the Sonos digital inputs, depending on the device, are only capable of reading optical, or HDMI-ARC, and only the Dolby Digital or stereo (PCM) codecs. Your Mac Mini would put out an HDMI signal, but not an HDMI-ARC signal.
A long winded way to suggest against this kind of usage. It can be done, but there is a lot of fiddling, and sometimes extra devices involved.
