<< Crossover levels are where the system cuts off the frequency... For your bass section, choosing a crossover of 100 would mean anything above 100Hz would be attenuated by either -6dB, -12dB, -18dB, or -24dB. The steeper the slope, the faster frequencies above the crossover level drops. -24dB is the steepest in this case. As for bandwidth, I am assuming they are meaning attenuation slope (-6dB, -12dB, etc etc). Same idea applies to treble - except any frequency Below your crossover point gets attenuated.
The idea here is to play around with those settings and see how your system sounds like as you adjust the settings. Everyone has their own personal taste. You just have to change around the settings until you get the sound you like.
Personally, I keep my sub crossovered at 100/-12dB, and midranges/tweeters at 100Hz/-6dB. >>
Pretty Much covered it....
Really depends on the size of your Speakers, what they're rated, how high your Subs will go, and how low your Mid/Hi's (or as we call it in Pro-Audio a Hi-Pack)or how they sound. A 2 way Crossover is gonna divide the Frequencies up into 2 signals, one for the Lows and one for the Mid/Hi's.
say you choose 60hz, anything lower than 60hz will play, higher htan 60 will be filtered
i believe it's low pass/hi pass, low pass 60 means filters anything above 60, hi pass 60 means filters anything below 60
Essentially, yes. It's isn't an exact cut-off, there is still some that is left over in each band, Bandwidth refers to this, how wide, or how many dB per octave slope (how many decibals per octave band they will cross into each other), and yes, bandwidth is a correct terminology, or 'Q' as it's also refered to. The higher the rating of the slope (24dB/Octave 36dB/Octave, etc....) the more effective it is at filtering out the frequencies on each side!
In a semi-related note - In a lot of our larger Concert rigs (I'm speaking of Pro-Audio, Live Sound PA's) we run the Hi-Packs Full range, and roll off anything under 45-50Hz, and run the sub-woofers from 75hz down. This creates an overlap in the bass frequencies, and help to de-couple bass frequencies off the ground and into the air a little more
Hope that clarifies it for you!