Earthworks IMB30 User's Installation Manual

IMBL30

IMB30

IMB30 & IMBL30

User & Installation Guide

30kHz Boundary Microphones

Frequency Response & Polar Response

The frequency response is measured with the microphone installed flush in a 3’ by 3’ rigid 

surface with incident sound waves hitting the boundary at a 45 degree angle. It is to be noted 

that the microphone’s low frequency roll off can be affected by the surface area of the bound-

ary. The frequency at which the boundary’s area starts to influence the low end roll off can be 

calculated by F=750/A, where A is the area of the boundary. 

Dimension Drawings

IMB30 & IMBL30 Frequency Response

45 Degrees Incidence

True Semisphere

™

 Polar Response

Frequency Response: 60Hz -30kHz ±2dB @ 45° incidence

Integrated Low Cut Filter: -15dB at 60Hz

Polar Pattern: True Semisphere™

Sensitivity: 70mV/Pa @ 1kHz

Power Requirements: 48V Phantom, 10mA

Max Acoustic Input: 136dB SPL

Noise: 19.5dB SPL (A weighted)

Output: XLR-3 (pin 2+)

Min Output Load: 1K between pins 2 & 3

IMBL Light Ring Connector: Phoenix or RJ45

IMBL Light Ring Voltage: 8-28VDC @ 85-170mA

IMBL Light Ring Activation: Momentary Digital Pulse

Microphone Color: Black, White or Silver

Weight: 0.28 lbs (125g)

Specifications

Earthworks, Inc. • 37 Wilton Road, Milford, NH 03086, USA 

Email: info@earthworksaudio.com • Phone: +1-603-654-2433 • Fax: +1-603-654-6107