I just bought a Velodyne 10" sub. The guys who sold it to me told me to NOT to use the x-over at all on the sub. They said the only knob i should be touching is the volume knob. So the switch for "phase and internal x-over", i put it on "phase" and set it to "0". Setting this to "phase"....then the "high pass crossover" and the "low pass crossover" doesn't work on the sub. So now i want the EXPERTS opinion's on what i should do I also have a Kardon 325 receiver and for my front speakers i have the JBL N38 floor standing. ( also i should i be setting my N38's as LARGE or SMALL" with this sub?) Thanks all.