Take a look at Audiomachina and The interview and Pearls is an interesting read.
Here is one quote from the interview:
" I guess if you are going to abandon first order, then, in a sense, it doesn't matter what you do. Everything is downhill from there. I think if I didn't have a choice to use first order, I would go straight to the fourth order, just because it gets you the benefits of the high order filters with the minimum number of driver drawbacks. But anybody who is using 12dB, for exampleÂand you see this all of the timeÂthere is a three way system and they are running 12dB per octave crossovers, and the midrange is wired in inverse phase. It is out of phase to the woofer and to the tweeter. It boggles the mind that people will put up with that as a transducer. If you feed a square wave into that, what comes out is going to look nothing at all like what went in."
Here is one quote from the interview:
" I guess if you are going to abandon first order, then, in a sense, it doesn't matter what you do. Everything is downhill from there. I think if I didn't have a choice to use first order, I would go straight to the fourth order, just because it gets you the benefits of the high order filters with the minimum number of driver drawbacks. But anybody who is using 12dB, for exampleÂand you see this all of the timeÂthere is a three way system and they are running 12dB per octave crossovers, and the midrange is wired in inverse phase. It is out of phase to the woofer and to the tweeter. It boggles the mind that people will put up with that as a transducer. If you feed a square wave into that, what comes out is going to look nothing at all like what went in."