The Shure Beta 91A is a condenser boundary microphone with a half-cardioid polar pattern optimised for recording low-frequency instruments and delivering a punchy sound with a good amount of attack in the process. The solid workmanship of the Beta 91A, with its robust housing and wire mesh, effectively safeguards the capsule as well as the internal electronics from potential damage. Shure declares the microphone as having a frequency range of 20Hz to 20kHz, with a sensitivity of 3.8mV/Pa, and a maximum sound pressure level of 155db at a load of 2,500 ohms. The microphone is operated with phantom power, the minimum and maximum permissible levels for which are 11V and 52V, respectively.
A glance at the Shure Beta 91A's frequency range in the spec sheet reveals a particularly well-emphasised attack sound and bass foundation. When the microphone is placed inside a bass drum, the proximity effect is especially responsible for a punchy sound, which remains precisely defined and does not become "boomy". At the same time, a pronounced range of 4kHz to about 9kHz ensures a distinct attack sound. A two-step contour switch with a centre frequency of 400Hz also allows unwanted frequencies to be reduced while recording without the need for additional equalisers.
The Beta 91A boundary microphone is designed primarily for professional use and features punchy bass and pronounced treble reproduction, ideal for recording percussion instruments. At the same time, its design and contour switch ensure quick and effective sonic results, simplifying the work of sound technicians, and pleasing the ears of the stick-slinging department with its full bass drum sound that cuts through any mix – all at a spot-on price-performance ratio.
The American company Shure began developing microphones during the early 1930s and is one of the pioneers of the audio engineering sector. Models such as the 55 Unidyne - known to many as the "Elvis microphone" - and the SM57 and SM58 which appeared in the mid-1960s are still ubiquitous in live sound production today. They enjoy cult status among musicians and technicians alike. In the 1990s, Shure introduced the first wireless microphones and in-ear monitoring systems and became a market leader in this field. In addition to microphones, Shure offers a wide range of earphones and headphones for studio and live use, as well as various accessories.
The special design of the Beta 91A condenser boundary microphone enables users to position it easily and discreetly without taking up too much room, eliminating the need for a space-consuming tripod. Its robust construction ensures a high level of durability against mechanical damage, making this boundary microphone perfect for use not only in a studio environment, but also on stage – no worries! In addition to recording percussion instruments like bass drums or cajóns, it can also be used for miking upright pianos or concert grands, in which case the holding eyelets underneath the sticker on the back come in handy: It simply needs to be placed on the bottom side of the piano lid – and it's good to go.