Complete instructions for this episode of Weekend Projects can be found at http://makezine.com/projects/bass-bump-headphone-amp/
Find more at the Maker Shed: https://makershed.com
Use dual LM386 amplifiers to build this portable two-channel bass bump headphone accessory. The amps will give you an added boost of low-frequency spectrum that will immediately change the way you listen to music. It's battery-powered and rechargeable so you can bump your jams wherever you go.