- The yellow arrows point to the original JBL speakers we saw during the first visit. This is a prime   example of a good product used in the wrong application. It "looks" right but the sound coverage   was extremely spotty with dead zones and hot spots. The ARTICULATION COVERAGE TEST©   revealed this problem to the board. It was instantly apparent why they had sound problems for   years.These speakers were re-used in the youth sound system in a more fitting application.