Toward the end of 2013 I was getting the itch to build something & I decided upon a THAM 12 tapped horn PA subwoofer, a design from Martinsson.
I ordered the wood as a flat pack from Tim Malone on the Speakerplans forums, who runs speaker-cabinets.co.uk dealing in CNC loudspeaker cabinets (both flat pack & assembled/finished).