Transmission linesare one of my favourite loudspeaker types. You make a tall hollow square wooden tube, or reduce the size by folding the tube and putting periscope-type sound-reflecting angled pieces on the corners. The drivers go at the top in the front, there's a port at the bottom at...
that, I suggest you buy from an engineering-first, low-bullshit manufacturer likeHeadroomorPractical Devices. Those people usually have abitof audiophile tinsel on offer, like expensive capacitor-upgrade kits that don't fare well in blinded tests, but they also have plenty of claptrap-free ...