Crossovers

[Guest mjasilli]

I am pretty new to this whole DIY audio thing, and have started pretty much at the simplest project I could think of, buildign a new crossover for a pair of free speakers I got from a friend. While I would say I have had success, the speakers have really come to life, I still have some issues about crossover design in general that I was hoping some of you could answer. I guess what I have found is that in the world of audio, nothing is ever simple. Now for the questions:

What order crossover should be used? While I recognize that this depends largely on the particularities of different speakers adn their drivers, I have come across general "rules" that I have questions about. I have read that the only crossovers worth building are first order and fourth order; you either want the first order for its unbeatable transient response, or the rapid frequency cut off of the fourth order -- anything inbetween is ill-advised because frequency cut-off is too slow and the transient response is negatively affected as well, they are a lose-lose. Other people claim that second and third orders are fine as well, and it really depends on how much money you want to spend on parts and how much frequency rolloff you need. I have also heard that at least a second order crossover is needed to protect a tweeter from getting to much low frequency and blowing in a two way speaker (I think that this really depends on the tweeter being used, because I know of some ribbon tweeters that claim responses from 500-25000 htz, granted they cost nearly $2000 each).

Thanks,

Matt