Nice!Make their sealed boxes ported. A friend of mine happily uses 6 of them, each in a 200-liter bassreflex box, tuned around low 20s. He says it hard to breathe when he turns up the volume.
I considered ported @ 13-15Hz but didn't want to make any compromises regarding port velocity and GD. I can feel 10Hz with my 4 subs and that's good enough for me