Measurement Microphones

Low cost measurement grade microphones are usually of the condenser type. They consist of a diaphragm and a back plate that act as a capacitor. The diaphragm vibrates in a sound field changing the capacitance of the microphone cartridge and an output signal is generated. Condenser microphones usually require an external supply in order to operate. This supply is called phantom power and is usually supplied from some sort of preamplifier. It consists of a three wire balanced circuit that incorporates two signal lines that are 180 degrees out of phase and one ground. The signal lines are amplified by a differential amplifier that rejects noise that is common to both.

The following characteristics are important in measurement grade microphones:

Low Distortion.
Low Internal Noise.
Flat Frequency Response,
Wide Dynamic Range
Stability over time and under severe environmental conditions
Ability to calibrate
Documentation and compliance with standards.

The following table compares seven condenser microphones

*Mike*	*ibf-akustik* *IBF-EMM8*	Nady Systems CM100 Measurement	*Beyerdyamic* *MM1* *Measurement Microphone*	*Behringer* *ECM8000*	*Audix* *TR40*	*Josephson* *Engineering* *C-550H measurement microphones*	*Earthworks Audio Products M23*
*Type*	electret condenser, omni-directional	electret condenser, omni-directional	electret condenser, omni-directional	electret condenser, omni-directional	electret condenser, omni-directional	electret condenser, omni-directional	electret condenser, omni-directional
*Phantom* *Power Requirements*	1.5 - 10V, ~ 0.5 mA	15 - 48V, ~2mA	12 – 48V ~3.4 mA	15 – 48V	9 – 52V	15 – 50V, ~2mA	48 V, ~10mA
*Sensitivity*	6mV/Pa	10mV/Pa	15 mV/Pa	1mV/Pa	14 mV/Pa	10 mV/Pa	30mV/Pa
*Impedance*	600O	600O	330O	600O	200O	50O	600 vO
*Peak Acoustic Input*	> 120 dB SPL	>120dB SPL	128dB SPL		128dB SPL	135dB SPL	142dB SPL
*Noise S/N ratio*	>58 dB		> 57 dB		77 dB		22dB SPL
*length*	315 mm	190mm)	133 mm				350mm
*max dia*	20 mm	22.22mm	19/9 mm			12.8mm
*weight*	42 g	120 g	88 g	120 g	140 g	140 g	160 g
*calibration*	Yes					Yes
*output connector*	RF phono jack	Gold-plated XLR	3-pin XLR male	gold-plated XLR		3 pin XLR	XLR
*On Axis response*	20-20000 Hz + 2dB	20Hz-20000Hz	50-16,000 Hz ± 1.5 dB	15-20000 Hz	20-19000 Hz +1/-3dB	20-20000 Hz±2 dB	9-27000Hz +/-1dB
*Response Graph*
*Polar Response*
*Picture*
*Cost*	US$45, €29	US$49, €31	US$60, €39	US$69, €44	US$240, €155	US$400, €259	US$500, €324

What We Do

Sonic beacon produces electrical and acoustical data acquisition and analysis software for the Windows operating system.

About Us

Sonic beacon is a Canadian organization founded in 1997. It is located in Pakenham Ontario which is near Ottawa, Canada. Ottawa is also home to the National Research Council of Canada's anechoic chamber, a key facility for acoustics testing. The chamber has been instrumental in the development of Canadian loudspeakers, hearing aids and microphone arrays.

News and Events

July 8, 2009: Sonic beacon Version 1.1.0.6 released. Data-Logger can now save in .FRD and .ZMA file format. Data-Logger and Spectrum Analyzer can perform .FRD and .ZMA clipboard copy transactions. Signal generator can output signal complements on each sound card channel to allow bridging in many consumer audio interfaces. Module status bar shows current data type, FFT size and sample rate.

Measurement Microphones

Nady Systems

CM100 Measurement

What We Do

About Us

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