Accordance with the above title How to make subwoofer using IC TDA2822, I want to share circuit diagram about IC TDA2822 for subwoofer speaker system. It cheap to built subwoofer audio system, by using subwoofer filter 4558 for filtering audio input and TDA2822 amplifier for driving subwoofer speaker. See the circuit diagram below:
Circuit Diagram TDA2822 Subwoofer
TDA2822 Subwoofer on circuit diagram above has mono output power about 20W (bridge output), it is small output power for subwoofer system. you can use small speaker size for using this amplifier.
Download: TDA2822 for Subwoofer System.pdf