A carefully tailored frequency rise at about 4,000 Hz makes the vocals stand out in the mix and yet keeps them smooth and easy on the ears. It's no surprise that the SM58 is the most popular mic in the world. The SM58 has a cardiod (unidirectional) polar pattern, 50-15,000 Hz frequency response, and is a low-impedance microphone. Consistently the first choice of performers around the globe, the SM58 vocal microphone is a genuine world standard and a true audio legend. The Shure SM58 is a unidirectional (cardioid) dynamic vocal microphone designed for professonal vocal use in sound reinforcement and studio recording. A highly effective, built-in, spherical filter minimizes wind and breath pop noise. A cardioid pickup pattern isolates the main sound source while minimizing unwanted background noise.