Can some one explain this alittle more?
That's explained about as well as it can be.
I have a Coustic XM6 and was woundering how crossover slopes put together would work. Is it a good thing or not?
Both.
Audio Rule #1; Nothing is "wrong" if the end result sounds better.
If it sounds better to combine two crossovers to achieve the desired results, then you did it right since it works for you. If it sounds worse, then it's wrong for your particular situation.
Is he saying that if you put a -24db/oct slope @ 80hz with a second -24db/oct slope @80 hz that you have -48db/oct slope but not @ 80hz?
Correct. The crossover point is technically the point at which the signal is attenuated by -3db. And since you would have two filters, each attenuating the signal by -3db, the result would be an attenuation of -6db at 80hz.....hence, it's no longer the
effective crossover point.
Combining filters isn't an easy subject. It gets more complicated if you start combining different filters, with different crossover frequencies and different slopes.
But, always revert back to rule #1. Just because you don't understand the mathmatics, doesn't mean your ears won't be able to tell you whether it was a "good" thing or a "bad" thing. If you have the necessary equipment...try it out, see how the sound differs.
BTW; thch knows his stuff. When you run across one of his posts, read them.