They sound very pure. you can distinctly hear the pure tones at 50hz (excursion minimum)
the distortion at 40hz,where excursion is 7mm (xmax is only 3.5mm!)
and then at 30hz and below,i can hear it in car,but its quiet.

with my new job,SPL meter very soon!

I hurt myself listening to it in car cant wait for SPL results! :P

Cheers~