Tangband Speaker kit

Folded horn speakers are fairly rare because they are expensive (the cabinets are more labor intensive) and because they are big (many designs reach 50").

Typically, there are multiple chambers inside that feed into each other, acting as a sort of acoustic amplifier for low frequencies -- think of a long horn, crunched up. The designer of this speaker kit solved the problem by putting the folding horn on it's side -- each piece is a cross-section of the speaker. Bolt/glue the sheets together, and you have a finished speaker. It has the advantage if being unique looking, rigid and economical to make on scale. Good design.