(Mis)understanding the Fletcher-Munson Curve
The Fletcher-Munson curve is often brought up in audio forums when people get into discussions of why you should or shouldn’t design speakers that measure flat. The curve, if you weren’t sure, is a graphical representation of how humans perceive relative SPL at a given frequency and is shown in in Figure 1, along with the ISO 226:2003 which replaced it, and is often referred to as an equal loudness contours. It’s often misunderstood, misrepresented, and judged in ways that ar
