Matti Kariluoma and a friend picked up a used guitar for a friends birthday, and wanted to add something special to it. They decided to build in some speakers, and whipped up a simple equalization circuit to correctly balance the high and low frequencies emanating from the modded axe.

I’m guessing music purists might shudder at the possibility for feedback with this setup, however it seems perfect for quick practice sessions without much setup, and maybe even for mobile performances.