David Bendeth, a producer who works with rock bands like Hawthorne Heights and Paramore, knows that the albums he makes are often played through tiny computer speakers by fans who are busy surfing the Internet. So he's not surprised when record labels ask the mastering engineers who work on his CDs to crank up the sound levels so high that even the soft parts sound loud. Over the past decade and a half, a revolution in recording technology has changed the way albums are produced, mixed and mastered — almost always for the worse. "They make it loud to get...