Wireless-speaker pioneer Sonos continues to expand beyond its roots with a new high-performance in-ceiling speaker designed and tuned in collaboration with Sonance, another pioneering company that helped launch the custom-installation industry 40 years ago with a new category of speakers designed for in-wall mounting. Slated to sell for $999/pair when it ships in the spring, the Sonos 8” In-Ceiling Speaker is a two-way model designed to spread full-range sound over a large listening area from behind an inconspicuous white grille that attaches magnetically to the speaker frame.