I agree with what UD says here.

At $349.99/ea (Guitar Center closeout special) the SxA100's are truly a STEAL. I was lucky enough to grab one at that price (from my local GC) earlier this week (for a musician buddy) who heard how great mine sounded at one of my recent wedding gigs. To fully maximize the EV's sound potential though, run your signal thru an external mixer. I use the Mackie 1202. I personally find the EVs bass sufficient for my shows without the sub woofer, but then again, I primarily play the kb & sing LIVE and don't do the DJ hosting (spinning CD's) thing, where continous heavy duty thumping (disco) bass is the main ingredient. If you require this, then the EV sub woofer may be what you want. GC is selling it for $349.99 but I'm warning you, the EV sub woofer (SxA180) weighs in at nearly 100 lbs.