What difference does the "order" make with x-overs

This is very hard (impossible I think)to explain in a short reply at a forum. For a decent short explanation (12-13 pages) try True Audio. www.trueaudio.com/st_mr1.htm. There are two parts to this article. the second substitutes "mr2" for mr1 in the original site.

Another short one is AudioControl at www.audiocontrol.com/techpapers/techpaper102.pdf

If you want more buy Vance Dickason's book Loudspeaker Design Cookbook.

You might also do a search at www.madisound.com (one of the better diy speaker building forums)under various words such as 2nd order, 3rd order. Some of the most common filters are given names Linkwitz-Riley, Butterworth, Bessel. Use those names too. There is a wealth of info at the Madisound forum on this topic and the proper use and effects of each type of filter.

Good Luck.

I remain,

One short addition to Ezmaralda11's fine explanation. An Octave is a doubling or halving of frequency. 20hz to 40hz is an octave. 40 to 80, 80 to 160 are also octaves. 3200hz to 1600hz is an Octave going down.

If a crossover is 2nd order it is going down 12db per octave. If the crossover is 2nd order and set for 3200hz it is going to roll off 12db by the time it reaches 1600hz. This is actually a bit of a simplification but it gives you the general idea. Read the articles I mentioned in the other post for a little more info.

Cheers,