A small mixer like the Yamah MG10XU would do the trick. Other pro audio companies like Mackie, Soundcraft, Presonus, etc. make similar products.
Basically, the both the Sonos outut and the output from the wireless mic receiver would plug into the mixer, and the mixer outputs would plug into the EV speakers.
https://www.sweetwater.com/store/detail/MG10XU--yamaha-mg10xu-10-channel-mixer-with-usb-and-fx
Regards,
Wayne A. Pflughaupt
Basically, the both the Sonos outut and the output from the wireless mic receiver would plug into the mixer, and the mixer outputs would plug into the EV speakers.
https://www.sweetwater.com/store/detail/MG10XU--yamaha-mg10xu-10-channel-mixer-with-usb-and-fx
Regards,
Wayne A. Pflughaupt