Kevin from Solar HiFi (http://www.solarhifi.com/) produces single driver speakers using the Jordan 92S with transmission line loading and recommends Adire subs (Rava, $400, for music and the Daeva, $600 with the 15 inch Tempest driver and digital amp, for HT).Don't know where you are on your audio journey, but I've looked into infinite baffle subs (inflexible), rear loaded horn subs (too BIG), transmission line subs (too complex), ported subs (don't control woofer excursion or match room gain), and for now have decided to just stay with simple sealed powered subs like the Adires.