I think it is a pretty nicely balanced system without obvious weaknesses. You should investigate properly before assuming that the Sonos is the weakest link. And if it is, you can, I think, redirect its digital output to your Marantz. That digital output will be bitperfect, and hence cannot be improved upon. A higher resolution than what the Sonos can deliver is impossible with current streaming bitrates so that does not argue for discarding the Sonos either.
Apart from the equalization suggestion that I made earlier, and given the size of the room, you might also consider adding subwoofers. It made quite a difference in my system. Go for at least two, and perhaps even four, like the Audiokinesis Swarm system. If you do, also apply room eq like the Antimode 8033. The room is the weakest link in any system.
Apart from the equalization suggestion that I made earlier, and given the size of the room, you might also consider adding subwoofers. It made quite a difference in my system. Go for at least two, and perhaps even four, like the Audiokinesis Swarm system. If you do, also apply room eq like the Antimode 8033. The room is the weakest link in any system.