Learn how to factory reset your SONOS One SL speaker. SONOS One SL Hard Reset should be done when you transfer a SONOS One SL to a family member or friend. The factory reset is commonly used when you need to register the SONOS One SL to another email address or to completely delete all stored data from a Sonos player, such as music streaming services like Spotify, Tidal or Apple Music also Sonos playlists. This operation cannot be undone.