Ninety-nine percent of earphones are designed to sound a specific way when placed in your ears: some are really bass-heavy, others are “flat” and neutral, and still others are tweaked to exaggerate both bass and treble. The pair that sounds really good with certain genres of music might not sound as impressive with others, and because of differences in some ears, a pair that fits one person might not fit another. Sleek Audio’s SA6…