Configure Speaker:  Ohm:  dual 1 dual 2   P Chamfer:  no yes +$10   Cooling:  no yes +$40   HiXmCoil:  no yes +$20   Daily or SPL:  Daily SPL   Induct Heat Ring:  no yes +$25   Universal:  no yes   I can't seem to find what these options mean and/or how eeach affects the end product and I would like to order a couple of the Fi 18" BLTs.  I will be playing them daily.  Does anyone know where these options are explained so that I can decide what to choose and why?