Home Slickdeals 12″ Monoprice Monolith 500W THX Ultra Certified Subwoofer Amplifier $699 + Free... Slickdeals 12″ Monoprice Monolith 500W THX Ultra Certified Subwoofer Amplifier $699 + Free S/H By ARCOM - 19 March 2021 51 0 SHARE Facebook Twitter Go to the deal page: 12″ Monoprice Monolith 500W THX Ultra Certified Subwoofer Amplifier $699 + Free S/H