Copperhead with Subwoofer 2.1 Channel Powered Desktop Speaker System Kit
How to make Down Firing Powered Subwoofer - DIY Build - YouTube
The Hammer DIY Subwoofer Build - GSG Kit - Order with code:Jilesgsg - YouTube
Amazon.com: CYOEST DIY Bluetooth Speaker Box Kit Electronic Sound Amplifier - Build Your Own Portable Wood Case Bluetooth Speaker Sound - Science Experiment and STEM Learning for Kids, Teens and Adults : Electronics