[Cpt Rick]

Very deep subject Randy, there are books written on it.

Depends on your needs IMHO.

Balanced is theoretically better and introduces far less noise, yet in the strictest sense of DJ'ing, I've never used balanced because of the noise floor and cost involved in maintaining a close to true balanced system on the road.

I generally use balanced everything in the studio though. Again, depends on what level of noise, hum, interference you are willing to put up with.

Other than just throwing a few XLR cables into the mix, you have to understand the whole signal flow from point A to point B, along with the underlying voltages, impedence, etc., to truly work a decently balanced system and match up all your components.

Unless you are doing it strictly for an audiophile purpose, or because you are pushing so much power that it makes it necessary to do so to avoid deafening people with hum and noise, I wouldn't worry about it for normal DJ use.