How many tweets can I run through a Crossover from a comp set? The cutoff freq will stay the same no matter how many speakers are being used, right? Would the bigger concern of this situation be to not try to throw a ton of power through the crossover (much more than the rated power for said comp set)? If I did, would the crossover fail at higher power (before the tweets-if not being fully powered)? Hope that makes sense.
I believe if the total ohm load is the same it will hold the same freq cutoff. The crossovers add resistance to the tweeter output so it gets less power then the main speaker.
Your best bet is to make your own crossover if you want to change the output speakers. If they are from a comp set they are designed for the speaker/tweeter combo.