Yeah, the Rythmiks are definitely interesting. I found measurements of the F12 here (https://docs.google.com/spreadsheets/d/1KjlXBWMPAHgU_V9DAHSdIZ_ke0MxwH6ekt3vTIlYOJU/edit#gid=0), which would be in the same price bracket as the ULS-15. Looks like between 20-31.5hz the Rythmik can do 109db...