Just two thoughts. Chicago may have a different setup from the last time I saw them, but a few years ago their backline was beneath them. Their stage is just a huge metal grating, and everything was just beneath their feet. Makes for a clean stage. Second, back to the OP, just yesterday I was at the Minnesota State Fair and walked near the International Stage. The bass from the Salsa band sounded so good I just had to go look. The rig was an electric upright going through a GK Microbass 150, which was sitting on a Bergantino HT112. He was running his internal speaker also so the Berg was only getting 75 watts (it's rated 300). I got behind the stage and could hear it fine by itself (not through the PA). The MB sounds good anyway with an upright, but running both speakers changed the bass to a more mellow tone. Really sounded nice.