Re: 5_1/4 vs. 6_1/2 How much of a difference?
A crossover blocks unwanted freqs from a speaker to prevent it from playing the freqs which it isn't capable of.
A HP-High pass, lets only the highs pass (at what ever selected freq you chose, or is fixed in a passive xover)
A LP-Low pass, lets the lows pass (at what ever freq you chose, or is fixed in a passive xover)
A BP-Band pass, lets a restricted band of freqs pass, an HP at one end and a LP at the other
A SSF, Sub Sonic Filter is a HP filter but at a low freq then the rest (~25-35Hz) to protect the sub.
A Passive xover is one that is a bunch of coils and caps and goes after the amp, between the amp and the speakers and has no power,
An Active xover has it's own power and goes some where in between the HU and the amp/s.