DISCLAIMER: As this topic is not ment for the average digital DJ that practices at home, plays at house parties, plays in clubs or most mobile DJs that cater to <250/300 people, my answers will assume a certain base level of knowledge. If you don’t know whay I am talking about (in general) when you read my answers, rest assured you don’t want to get deeper into live sound.
All answers I give in this topic are, obviously, IMHO. They are, however, based on both theoretical and practical knowledge and experience and will usually reflect industry best-practices.
I will be slightly more outspoken on gear issues (brands, models, types of gear) than I will be in other forums/topics. I will be more inclined to tell you about the stuff I have used. Not to say it’s better, but just because I have more knowledge of it and thus better insight into something being suitable to the person stating the question.