DIY coaxial speakers Eminence SBacoustics subwoofer
Made from the idea of a very coherent top and subwoofer below it to go plenty deep. They do around 28 Hz (-3dB). Inspiration was a DIY build by a member of the Dutch DIY audio website:
zelfbouwaudio....
My version is a bit more on steroids. :-) My tops also have the same 'labyrinth' inside design as the Nescio.
Also the Tannoy D700 was an inspiration sizewise but also soundwise.
Here some more info on the build:
zelfbouwaudio....