For a century, engineers have developed countless equalizers. A few became legend, our thEQorange is one. The most popular version in recording and post is the parametric equalizer or PEQ, first perfected by Massenburg in 1972. It offers maximum flexibility with only three controls. Properly used, the PEQ is a powerful tool and the best friend of every audio engineer in the quest for perfect sound. As Spidey (and Voltaire) always reminds us though, “With great power comes great responsibility.” When designed by a clueless or cost–constrained software engineer, it can truly degrade your work.