On June 9, 2022 at 17:23, Fred Harding said...
I would suggest that you are using consumer level outputs on the Sonos, and the Crown is looking for a pro level input. There's a 14 dB difference between the two. You'll need a line driver to act as a stepping preamp between the Sonos and the Crown. RDL makes a dandy one. Others are out there as well.
+1