PA Setup Questions

Ok, i've been using a pretty simple PA system for my shows for about a year now. Just 2 Peavey PR12's and a old school powered mixer. I'm looking to add a subwoofer to it because im starting to play for bigger crowds and need the 'omph' of the bass to be felt. I'm looking to go with an unpowered mixer and a power supply since my current mixer only has one input for the speakers on each channel, and I was wondering if I would have the wiring down correctly. It would go: Speakers and Subwoofer-Mixer-Power amp. (- representing wires) I don't know much about PA's so any help would be nice. Thank you

I'm fairly PA ignorant, but I'm sure you will need a crossover unless the sub has one built in. Also the signal chain would be mixer-crossover-amps (1 for speakers & 1 for sub)-speakers/sub

Most amps have a link output which enables you to connect them to the next amplifier. Using a crossover will give you a quality and volume boost though, and it has all the output functionality you need. (1 stereo in > 1 output for the top speakers and 1 output for the subwoofer.)

thanks guys!

I dont think i understood your post properly, but my setup, and most mobile setups are
mixer-crossover-sub amp(from sub out) to sub and speakers(from mid/hi out) to speakers if that makes sense.
You wouldn't usually have the mixer in between the amp and speakers, you would have it first.

ok cool, so I found an amp that says it has pureband crossover capabilities. Does that mean it has a crossover built in?

PureBand Crossover System
"The PureBand Crossover System in the Crown XLS Series power amplifiers adds an enormous amount of flexibility and performance to any system. With this system, the crossover frequency is completely variable allowing the choice of any crossover point between 50Hz and 3kHz on 1/12 octave centers. The use of 4th order Linkwitz-Riley filters provides steep slopes for a seamless transition between high and low drivers. And with four crossover modes to choose from providing the ultimate in flexibility, all of your system needs are covered. "