That thing has NO treble response, I'd be onry enough to get some cheap ($5.00 each)piezo tweeters and mount on top of each horn, just to see what happens to the sound.
Are you playing through the large Crown amplifier, or using something smaller.
Here's the "Brock's Dub" of Friday, my geometry teacher showed this to my class. Just so you all know, there's some language in there that isn't exactly appropriate. Important message towards the end though.