½-inch Free-field Microphone, Externally Polarized, 6.3 Hz – 20 kHz

Type 4190 is designed for high-precision free-field measurements where a microphone with high sensitivity is required. Being externally polarized, Type 4190 must be used with classical preamplifier.

USE SCENARIOS

• Precision sound measurement
• Premium class sound level meters
• Equipment complying with IEC 61672 class 1

USE OF FREE-FIELD MICROPHONES

At higher frequencies, reflections and diffractions cause a pressure increase in front of the diaphragm of a microphone. If not corrected for this would result in an increased output voltage.

A free-field optimisation means that the frequency response of the microphone has been designed in such a way that the free-field response at 0 degrees incidence is flat. This microphone is optimised for use with the protection grid in place.

Free-field microphones are commonly used for sound measurement in an anechoic chamber or far away from reflecting buildings, etc. Another area for free-field microphones is for general electroacoustic measurements like loudspeaker and microphone measurements.

Type 4190 is not only suited for use in class 1 Sound Level Meters but also for all high-precision acoustic measurements where a robust and stable, externally polarized free-field microphone with an upper frequency of 20 kHz is required.

STABILITY

A press-fitted, stainless-steel diaphragm ensures superior long-term stability and mechanical robustness – Type 4190 will withstand the 1 m drop test of IEC 60068-2-32.

POLARIZATION VOLTAGE

Type 4190 requires an external polarization voltage and must therefore be used with a classical preamplifier. Externally polarized microphones may be used at higher temperatures without severe changes in sensitivity.

Type 4190 is available in TEDS combinations with the classical Microphone Preamplifier Type 2669. The TEDS microphone is considered one unit and has been sealed in a clean environment.

The TEDS is programmed with the loaded sensitivity of the actual cartridge and the data is therefore readily available. The default TEDS template is to IEEE P 1451.4 but TEDS to IEEE 1451.4 is available on request.