Next, let's look at three typical PA setups, all of which you can build with equipment available from the Thomann Cyberstore.
The basic band PA
This is pretty much the minimum requirement for a band or small venue that wants to create a decent sound. You have two mid/high range 6.5" speaker cabinets, an active 12" subwoofer, and a mixer. (If you don't need much low end, you could get away without the subwoofer.)
This is a good standard setup for larger venues and bands looking for a more professional sound. It can handle most small and medium-sized venues, and some outdoor settings. You have two full range 12" active speakers and two 18" subwoofers. This configuration also gives you a high degree of flexibility, because you can leave one or both of the subwoofers behind for smaller venues.
DJ and band
Discos and bands have significantly different requirements, so a big event featuring both types of performance requires a versatile and powerful system. The biggest challenge is the amount of bass pumped out by the disco, which can ruin the whole sound with distortion if not properly managed.
The example shown here can handle high volumes across the whole frequency range. It consists of two coaxial horns, four 1x18" subwoofers, and a rack of power amps with a crossover to manage the frequency division.
In all cases, the key question is: how much power will you need? And remember, the answer is about the quality of the sound, not just the volume. Consider the venues you're likely to be playing, and make your choice on the basis of the type of sound you want to create. Clearly, a jazz band will have different needs to a heavy metal band, but all good musicians will want the sound out front to be as true to their musical vision as it possibly can be.