parabolic loudspeakers
... that one of the public address applications of parabolic loudspeakers is to project sound waves in a 10° cone pattern 300 feet (90 m) away?
... that one of the <a class="mw-redirect" href="./Public_address" id="mwMQ" rel="mw:WikiLink" title="Public address">public address</a> applications of <b id="mwMg"><a href="./Parabolic_loudspeaker" id="mwMw" rel="mw:WikiLink" title="Parabolic loudspeaker">parabolic loudspeakers</a></b> is to project sound waves in a 10° cone pattern <span about="#mwt14" data-mw='{"parts":[{"template":{"target":{"wt":"convert","href":"./Template:Convert"},"params":{"1":{"wt":"300"},"2":{"wt":"ft"},"3":{"wt":"m"},"4":{"wt":"-1"}},"i":0}}]}' id="mwNA" typeof="mw:Transclusion">300 feet (90</span><span about="#mwt14" typeof="mw:Entity"> </span><span about="#mwt14">m)</span> away?