A live/rave sound system is nothing like home theater system. Live systems use high powerer amps that often have limiting/compression and crossovers built in, the speakers are designed to cover a specific area instead of offering a pleasing image, the acoustic space is usually much larger and equalization is done for impact, not sound effects. The difference is the size of the space where the music is played is part of why it sounds the way it does. A small room (even a large one by residential standards) just won't sound the same because a large space allows the sound to "breathe" in a way a small room can't. The standing waves in a small room ruin the bass but in a large space with a system that uses horn loaded drivers, line arrays and thousands of watts, the room doesn't react to the acoustical energy the same way as a smaller one using speakers that are made for great dispersion/imaging, THX approval, "depth and transparent sound".
Another thing that makes a live/rave system sound great is the ability and knowledge of the person operating the system. We have all heard bad live sound- I would bet everything I own that this is true because I have talked with sound guys who had absolutely no idea how to get good sound. These guys never use any equipment when they equalize, think their ears are so good that they always make it sound great are always messign with all of the controls, usually without much luck.
Formoz- if you really want to build a system that works for raves and gives you the sound/feel you described, go to a store that specializes in PA systems, not residential equipment. They are completely different. The connections are different, the cabling/connectivity is different, the speakers are made to focus the sound and not for wide dispersion and some is actually made to run on 220/240V. Also, pro equipment is designed and selected using different criteria- real specs, not characteristics that are often completely imaginary or caused by the marketing departments of the equipment/cable companies. You won't see $1500 power cords, audio cables that will supposedly change your life and win the war for the Allies or any of that crap. This stuff meets the specifications of the system designer. Period. It's made to be durable and to be connected/disconnected many times, not to be lovingly inserted and hugged. It generally doesn't sound the same as consumer grade equipment and there's really no reason it should- it's made for a different purpose- covering a large area vs imaging to make a 5.1 mixed CD or DVD sound like you're in the middle of the action.
Another thing you'll need to consider when trying to use this in an outdoor environment- with no walls and ceiling to reflect the sound, your system's output will be nothing like what you hear at an indoor rave. The sound may be good up front but once you move back, the volume will drop off considerably unless you use more speakers to cover the areas not handled by the main speakers (one of the reasons for line array systems). You won't have enough power with one or two amplifiers, regardless of the size of the generator. You'll also have to think about how far the bass carries outdoors and who will call to complain about the noise. If you can get a permit to do this in a park, it may be OK but if that area is near residential areas, plan on seeing the police at least once every time.
