Boomstack is a study of how sheet metal could be used in the field of high-end home audio. It won an honorary mention in Plootu Fennica 2014 design contest.
This subwoofer concept is designed with scalability in mind. Different room sizes eat up different amounts of bass. A system that is sufficient in small basement cinema can run out of punch when placed in a large loft apartment. Boomstack units can be simply piled on each other until wanted capacity is met. These passive subwoofers can be connected in both series and parallel for flexible impedance management.
Enclosure is made from laser cut and tensioned aluminium sheet metal. When bent into spiral, the otherwise floppy material becomes very stiff. Curved walls reinforce top and bottom plates while taking up minimal amount of internal volume. Depending on application, the spiral enclosure can utilized both for sealed box and transmission line operating principles.