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: [email protected] • Phone: +1-603-654-2433 • Fax: +1-603-654-6107
