Amazon.com: Arylic Subwoofer Amplifier Board,WiFi & Bluetooth Home Audio Amplifier Board for DIY Speaker Kit.Wireless Connection Multiroom/multizone Sync Play for Airplay DLNA - Up2stream Amp Sub : Electronics
WW Speaker Cabinets Introduces 21-Inch Subwoofer for DIY Home Audio Market | audioXpress
LG Wireless Rear Speaker Kit-SPJ4S with Subwoofer Home Speaker - SPH4B-W | eBay
Acoustech WIRELESS H-100II – Wireless 500W 12” Front-Firing Subwoofer with Lacquer, for Home Theater & Music – BIC America