Shure
Beta 91A
Boundary · Cardioid · 20–20,000 Hz · a rider regular
- Half-cardioid: the boundary surface is part of the microphone, so its pattern only exists in the hemisphere above whatever you lay it on.
- The A revision moved the preamp and XLR into the body — the separate in-line preamp of the original Beta 91 is one less thing to lose in a drum case.
- The contour switch takes about 7 dB out around 400 Hz, which is the cardboard the beater end of a kick usually needs removing.
Frequency response
Read off Shure’s published response graph and re-drawn on the fixed MicSense scale (20 Hz–20 kHz, −20 to +15 dB), so two microphones can be compared at a glance. Points between the entered coordinates are interpolated — no data has been invented to smooth the curve.
Polar pattern
Generated from the first-order directivity formula for cardioid. It illustrates the pattern type — it is not a measurement of this individual model.
Specifications
| Manufacturer | Shure |
|---|---|
| Model | Beta 91A |
| Type | Boundary |
| Form factor | Boundary |
| Polar pattern | Cardioid |
| Frequency range | 20–20,000 Hz |
| Sensitivity | 3.8 mV/Pa · -48.5 dBV/Pa |
| Max SPL | 155 dB SPL |
| Self-noise | — |
| Impedance | 146 Ω |
| Connector | XLR3M |
| Powering | phantom 11–52 V |
| Weight | 470 g |
| Price tier | Pro |
| Introduced | 2010 |
Every figure above is from Shure’s own published datasheet for this model — see the datasheet. A dash means the manufacturer does not publish that figure; it does not mean zero.
What it gets used for
- Kick in
- Acoustic instrument
- Lectern / podium
MicSense tags microphones by the job on a live stage, not by studio category — so you can filter for “kick in” or “monitor vocal” instead of working backwards from “large-diaphragm condenser”.
Compare it against the alternatives.
MicSense lets you put up to four microphones side by side — spec table, overlaid response curves and polar diagrams on one screen. Free with a free Squaresmile account.