I'm looking to build a rig for outdoor events this summer. I currently have a ul502/ul410 setup, which is fantastic. For outside events, I'll be using the ul502 as a preamp, and using a Crest CA9 as a poweramp powering a stack. My dilema is, should I stack a ul410 with another ul410, or with a ul115? I'm looking to achieve more volume, AND actually FEEL my bass during large outside shows.