[. . . ] 2 General Description The Shure Beta 91A is designed for use with kick drums, piano and other traditional low frequency applications. An updated microphone capsule is tailored for bass-heavy environments to produce a powerful low frequency response, and a new design integrates the preamplifier and XLR connection for easy setup and minimal stage clutter. [. . . ] €¢ Do not cover any part of the microphone grille, as this will adversely affect microphone performance. The following table lists the most common applications and placement techniques. Keep in mind that microphone technique is largely a matter of personal taste; there is no one “correct” microphone position. Experiment with lid height and placement to hammers for desired sound. Mount microphone vertically on the inside of the piano frame, near the apex of the piano’s curved wall. €¢ Two-position contour switch enhances attack and clarity • Integrated preamp and XLR connector reduce stage clutter and provide a quick, secure setup • Low profile design requires no external mounting hardware • Steel grille and die-cast metal construction resist wear and abuse Performance Characteristics • Exceptional low-frequency reproduction • Extremely high SPL handling • High output level • No crossover distortion Note: Location and room acoustics strongly affect the sound quality of microphones. To achieve the best overall sound for a particular application, it may be necessary to experiment with microphone placement and room treatments. Mounting the Microphone For long-term installation, mount the Beta 91A to a surface using the mounting holes on the bottom of microphone. Contour Switch A two-position switch on the bottom of the microphone lets you selectively filter the low-mid frequency response without additional tools. Use this filter to enhance the attack and clarity of bass-heavy instruments. EQ EQ Low-Mid Scoop: This setting tailors the microphone’s frequency response to provide a strong ‘punch’ in the low frequencies, and plenty of attack in the higher frequencies. 3 Load Impedance Maximum SPL capability, output clipping level, and dynamic range vary with the input load impedance of the preamplifier to which you connect the microphone. [. . . ] ) 1 Pa=94 dB SPL [2] THD of microphone preamplifier when applied input signal level is equivalent to cartridge output at specified SPL [3] S/N ratio is the difference between 94 dB SPL and equivalent SPL of self noise, A-weighted [4] All specifications measured with a 48 Vdc phantom power supply. The microphone operates at lower voltages, but with slightly decreased headroom and sensitivity. [. . . ]