Amazon.com: Audiobank 1/2 Din Car Audio Digital Bass Processor, Sound Restoration & Crossover for Car Subwoofer with Bass Knob/Input Level: 15V RMS & Output Level: 13.5V Peak : Electronics
Frisby Audio 125 Watt Home Theater 5.1 Surround Sound Speaker System with Subwoofer, Bluetooth Wireless Streaming from Devices & Media Reader, RGB LED Pulse Lighting, Digital Optical Input – Black - Newegg.com
JL Audio Fathom F112V2 12 Inch Powered Subwoofer Black Gloss — Safe and Sound HQ
AIYIMA B01 2.1 Channel Bluetooth Amplifier Receiver with Subwoofer Output 50W +50W +100W Class D Integrated Amp - Walmart.com