I'm referring to a active crossover of high quality and precision I will be using it on a reggae sound system for(bass,low mid,mid,highmid,high)20hz-30khz or close
Does this mean that it has to handle just line level upstream of several sets of amplifiers? If so, some time spent with FilterPro (free download from TI's website) will provide you with high and low pass opamp filters tailored to your specs. You have to know the cutoff frequencies and how many poles per filter, though.
Why don't you buy a commercial crossover? If you don't know what you're doing you're gonna waste more time and money playing around than if you'd just bought one in the first place.
I did a quick google search and came up with this thing. 10 Channel Active Crossover Network - OPTIX10 - Buy.com
That would act as a mixer before the actual amplifiers, and you'd use separate amplifiers for each channel. I'm sure if you look around long enough you'd find something cheaper or more modest to meet your exact needs.