i played mp3 file (30Hz tone 128kbps) downloaded free from http://www.testsounds.com/
box (for 2 18" single coil 3") setting (approx) @ 55Hz (recalculate using tool from web --> http://www.the12volt.com/caraudio/boxcalcs.asp )
next step will change with new box, new amp, and new sub (i wish)
