4-channel amps

would anybody know if 4-channel amps are bad to have the first two channels to tweeters with caps and the other two for mids? and if its stable to 2 ohms, would it "clip" if all the highs and mids were 4 ohms ea? its 75x4 @ 4 ohms. if anyone knows. can you give some insight. thank  you.

Yes, it is possible to bi-amp your system as you describe.  If all your speakers are 4-ohms and you are connecting one speaker to each output channel of the amp, the amplifier will be fine and will run at 4-ohms.  If you are using an electronic crossover, you will not need "caps" on your tweeters (assuming the crossover has both a high-pass output for the tweets that you can set up around 3500Hz or so, and a band-pass for the mids.)  What are you doing for bass?  Make sure you know the required crossover frequency for those tweeters or you can blow them very easily.  Also, the amplifier power needed for the highest frequencies is less than 30% what is needed for lower frequencies, so if you run 75 watts to the tweeters (assuming they can handle this much power) you will most definately need some sort of trimming potentiometer or some sort of input limiting device so you can match their output to the mids.  Otherwise, expect a really harsh high end that is way too loud and will overpower the sound.