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Earthworks CTB30-B - Omni Boundary Layer Table Top Microphone - Black

£699.00 inc. vat
£582.50 ex. vat
Please contact us for availability.

Earthworks CTB30-B

The Earthworks CTB30-B is a Black boundary microphone designed to keep a low profile on or in ceilings and tabletops for conferencing and other speech applications. The CTB30 incorporates a unique filter that significantly reduces low frequency table thumping and HVAC noise. Additionally, it delivers an impressive reduction of unwanted sounds from paper shuffling.

The Earthworks CTB30 boundary microphone is the perfect choice for high quality conferencing applications. Its extended high frequency response to 30kHz and Omni Semisphere™ polar response provide the same high intelligibility at virtually any point around a conference table or other surface on which the microphone is mounted. In addition, the extremely fast diaphragm settling time allows more subtle details and nuances of the human voice to be reproduced, which adds to the incredible clarity and intelligibility of the CTB30 at various distances from the microphone.


Measuring just 4.1 inches in diameter, the CTB30’s sleek design fits seamlessly into any room. It comes with a 10 ft (3.04m) low profile cable with XLR-3M attached, which is designed to exit from the side or bottom of the microphone. The XLR can be removed, allowing the cable to run through a small hole in the table surface for permanent installation. Two 6-32 screw holes and a keyhole are found on the bottom of the microphone for secure mounting, if required.


  • Specially engineered filter to minimize table thumping and HVAC noise
  • Reduced pickup of paper shuffling
  • 30kHz frequency response optimized for speech
  • Ultra high intelligibility
  • More gain before feedback
  • Near perfect polar pattern
  • True Semisphere™ omnidirectional polar pattern
  • RF resistant
  • Rubber, shock absorbing pads eliminate vibration noise
  • Designed to allow cable to exit from the rear or bottom of the microphone
  • Low profile design
  • Only 4.1 inches (10.4cm) in diameter
  • Available in black, white, stainless steel or Nextel® Dark Black finish
  • Primary applications include teleconferencing, distance learning, surveillance, boardrooms, government facilities, worship facilities and ambient room miking


  • Frequency Response: 60Hz to 30kHz -3dB @ 1 ft (30cm)
  • Low Frequency Rolloff: 60Hz, 15dB/octave
  • Polar Pattern: Omni Semisphere™
  • Sensitivity: 60mV/Pa
  • Power Requirements: 24-48V Phantom, 10mA
  • Max Acoustic Input: 136dB SPL
  • Dynamic Range: 116dB @ 1kHz
  • Output: XLR-3 (pin 2+)
  • Output Impedance: 65Ω balanced
  • Min Output Load: 1K between pins 2 & 3
  • Noise: 20 dBA (Typical)
  • Microphone Color: Black
  • Dimensions: 4.1 x 4.1 x 0.45 inches (104.1 x 104.1 x 11.4mm)
  • Cable Length: 10’ (3.04m) with installed XLR-3M
  • Connector Type: Low profile cable terminated into a 3-pin XLR-M
  • Weight: 0.36 lbs. (162g)