Years ago I built a 2x6" cabinet with a pair of Faital 6FE100s, exactly the size of my largest pannier bag so I could cycle to gigs with it. It turned out, mostly by accident, to be a success, and more recently I've been using it a bunch for double bass gigs. However at ~8kg or so it's still quite a lot of stuff to carry alongside a big bass, and I'm often playing drumless so I never turn it up past halfway anyway.
So after stumbling across @Phil Starr's micro cab design I thought I'