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Shure

collapse expand iconDescription

The Shure RPM181/BI is a bidirectional condenser capsule for the versatile Shure BETA 181 microphone. The BETA 181/BI capsule is ideal for mono drum overheads, and dual instrument sound source applications.

The Shure BETA 181 (sold separately) is a multipurpose instrument microphone and can be used on a wide variety of applications including guitars, bass and drums (overheads and snares). It has a small-diaphragm design that provides superior audio with textbook polar responses in a form factor compact enough to get close to the source in the tightest conditions.

There are four different capsules available for the BETA 181 microphone: This Bidirectional (RPM181/BI) version, as well as a Cardioid (RPM181/C), Supercardioid (RPM181/S) and Omnidirectional (RPM181/O). This makes the BETA 181 an extremely versatile and cost-effective mic that allows the user to interchange capsules according to the application. (Additional capsules sold separately).

Shure RPM181/BI Bidirectional Capsule for BETA 181

collapse expand iconFeatures

  • A bidirectional capsule for the Shure BETA 181 mic
  • Ideal for mono drum overheads and dual instrument sound source applications

collapse expand iconSpecs

Cartridge Type
  • Electret Condenser
Polar Pattern
  • Bidirectional
Frequency Response
  • 20Hz to 20kHz
Output Impedance
  • 110 ohm
Sensitivity (open circuit voltage, @ 1 kHz, typical)
  • -51dBV/Pa (2.6 mV)
Maximum SPL (1kHz at 1% THD)
  • 2,500 ohm load: 156dB SPL
1,000 ohm load: 153.5dB SPL
Signal-to-Noise Ratio
  • 71dB
Dynamic Range
  • 2,500 ohm load: 133dB
1,000 ohm load: 130.5dB
Clipping Level @ 1 kHz, 1% THD
  • 2,500 ohm load: 10.5 dBV
1,000 ohm load: 7.5 dBV
Self Noise (equivalent SPL, A-weighted, typical)
  • 22.5dB SPL-A
Common Mode Rejection (20Hz to 20kHz)
  •  ±55dB
Polarity
  • Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3
Power Requirements 11–52V DC phantom power (IEC-61938)
  • 2.4 mA, maximum
Capsule Width
  • 1.36" (34.54 mm)

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