Soooo, It's really just the crossover then? I been looking at just raw speakers and they are pretty much the same. So buy a cheaper p.a. cabinet and take out the crossover. Why does a bass cab cost twice what a p.a. cab cost when the p.a. has more to it? Just because it says Peavy or Fender on it?
You are mixing up PA speakers with PA subwoofers.
A full range PA system reproduces the entire tonal range.
A PA subwoofer only produces the bottom end.
If there is a crossover in a subwoofer, it is there for one of two purposes.
1) To stop the high frequencies from being reproduced. This is not to protect the subwoofer, higher frequencies are not going to hurt it, they just either can't be reproduced or they sound like cr@p when they are.
2) To prevent extremely low frequencies below those the sub is designed to reproduce from going through because those can damage the speaker.
A proper bass cabinet is about the equivalent of a PA with no tweeters. It produces what are considered to be subwoofer frequencies all the way up into the lower end of the midrange. They just don't need to reproduce high frequencies, so they don't.
A PA system on the other hand might have to produce everything from the lowest bass notes to the brightest, most delicate sounds something like a flute can produce and everything in between.
A PA sub is just one piece of a proper PA system. You would still need full range speakers to cross in for everything above the subwoofer frequencies. It is possible to buy speakers that do not need the reinforcement of a subwoofer, but they aren't cheap.
