I don't think the actual speakers or the announcers are the problem, but rather the way in which the PA has been acoustically set up. A number of things could be done to improve it including ringing out the system of reflective frequencies, EQ'ing out the boomy low ends and boosting around the 2-5k mark, lowering the crossover point for the LF speaker cones (if we have one), and mainly - reinforcing my previous post - making sure the sound controller is actually based in the seats of the stadium.
(I know these things won't mean anything to most people but at least it may provide possible tips for the sound guys at HP
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