Use a third-party subwoofer with Amp or Connect:Amp | Sonos
Amazon.com: AIYIMA A300 NE5532*4+QCC3034+TPA3255 Bluetooth5.0 300w*2 Power Amplifier Support aptx-hd 2.0/2.1 Channel Amp with Active Subwoofer Output for Passive Speaker Home Audio : Electronics