Shure RPM181/PRE Replacement XLR Preamplifier for Beta 181 Condenser Microphone

The RPM181/PRE Replacement XLR Preamplifier by Shure is designed to work in combination with one of four interchangeable capsules for the Shure Beta 181 side-address instrument microphone. The capsules come in cardioid, supercardioid, omnidirectional, and bidirectional polar patterns, making a highly versatile pair.

With a capsule attached, it weighs only 5.1 oz and can get close to any source even in the tightest conditions. Its wide frequency response and high SPL handling are great for miking dual sound sources, such as between toms or acoustic instruments. It is also very useful as a mono drum overhead, or pair two to create the Blumlein stereo effect.

The RPM181/PRE matched with any of the available capsules performs with little to no crossover distortion and provides exceptional low-frequency reproduction. The pair provides exceptional audio with consistent, textbook-like polar responses, resulting in a mic with noteworthy sound and versatility.

Features:

• Works with one of four interchangeable capsules for the Shure Beta 181 instrument microphone
• The cardioid, supercardioid, omnidirectional, and bidirectional capsules make this mic highly versatile
• Weighs only 5.1 oz with attached capsule and captures any source even in the tightest conditions
• Matched with any available capsule it performs with little to no crossover distortion and provides exceptional low-frequency reproduction

Specifications:

• Type: Condenser
• Frequency Response: 20 to 20,000 Hz
• Polar Pattern:
  • 181/C: Cardioid
  • 181/S: Supercardioid
  • 181/O: Omnidirectional
  • 181/BI: Bidirectional
• Sensitivity:
  • Cardioid: -46.5 dBV/Pa (2.4 mV)
  • Supercardioid: -49.5 dBV/Pa (2.5 mV)
  • Omnidirectional: -52.0 dBV/Pa (2.6 mV)
  • Bidirectional: -51.0 dBV/Pa (2.6 mV)
• Output Impedance: 110 ohms (at 1 kHz)
• Signal to Noise Ratio:
  • Cardioid: 73.5 dB
  • Supercardioid: 71.5 dB
  • Omnidirectional: 70.5 dB
  • Bidirectional: 71.0 dB
• Self Noise:
  • Cardioid: 20.5 dB SPL-A
  • Supercardioid: 22.5 dB SPL-A
  • Omnidirectional: 23.5 dB SPL-A
  • Bidirectional: 23.0 dB SPL-A
• Common Mode Rejection: ≥55 dB
• Polarity: Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3
• Power Requirements: 11-52 V DC phantom power (IEC-61938), 2.4 mA maximum
• Maximum SPL:
  • 1000 Ohm Load:
    • Cardioid: 149.0 dB SPL
    • Supercardioid: 152.0 dB SPL
    • Omnidirectional: 154.0 dB SPL
    • Bidirectional: 153.5 dB SPL
  • 2500 Ohm Load:
    • Cardioid: 151.5 dB SPL
    • Supercardioid: 154.5 dB SPL
    • Omnidirectional: 157.0 dB SPL
    • Bidirectional: 156.0 dB SPL
• Dynamic Range:
  • 1000 Ohm Load:
    • Cardioid: 128.5 dB
    • Supercardioid: 129.5 dB
    • Omnidirectional: 130.5 dB
    • Bidirectional: 130.5 dB
  • 2500 Ohm Load:
    • Cardioid: 131.0 dB
    • Supercardioid: 132.0 dB
    • Omnidirectional: 133.5 dB
    • Bidirectional: 133.0 dB
• Clipping Level:
  • 1000 Ohm Load: 7.5 dBV
  • 2500 Ohm Load: 10.5 dBV
• Weight: 5.1 oz (145 grams)