i have 2 morel dms-29 1-1/8 tweeters. what would be the difference in sound if i used a capacitor instead of running the speakers thru a crossover? does it affect the power it receives?

A single capacitor is a simple 1st order crossover when chosen correctly.

What exactly are you trying to do?

i want to wire my tweeters and mid drivers without using a crossover. the sales rep i spoke to told me that was the easiest route to go. i dont have any specific goals other then for the speakers to work and not blow. or sound bad.

what mids? what h.u? what amps? what mounting locations? what car?

you definitely want crossovers on your tweeters or they'll blow the first time you play music loudly. They won't like that bass. and the mids will probably not get too loud without the lower bass distorting them as well, and they may break up and sound bad in the high frequencies where the tweeter should play. So....long story short, that salesman told you some bad advice.