Guide for Electret Condenser Microphones A microphone as an audio-electric converting device, whose audio pickup section has a structure of a condenser consisting of a diaphragm and a back plate opposite thereto, is called a condenser microphone. The motion of the diaphragm by sound is picked up as a variation of capacitance between the diaphragm and the back plate. In this case, usually, a voltage of tens or hundreds of volts should be applied extermally as a condenser polarizing voltage. However, electric charge can be maintained in a polymer film by the electret effect, thereby eliminating the polarizing direct-current high voltage. Such is an electret condenser microphone. In structure, electret condenser microphones are grouped into the following three types according to where the electret film is used: q w q e qfoil-type electret condenser microphone The diaphragm itself is made of an electret polymer film. wback-type electret condenser microphone Contrary to q, a polymer film is adhered to the back plate. efront-type electret condenser microphone The back plate is structurally eliminated. The diaphragm and the inside portion of the microphone capsule itself form the condenser. The electret is located inside the case. Structural schema of Electret Condenser Microphone Sensitivity The sensitivity is defined as the output voltage for a specified acoustic stimulus and load condition. In this catalog it is expressed in dbv/pa (dbv/0μbar). In the case of dynamic types it is expressed as the open circuit voltage appearing at the output terminals. In the case of electret type it is expressed with a specified resistive load and supply voltage since the output resistance tends towards constant current characteristic. Output impedance The output impedance represents the internal electric resistance within a microphone as seen from the side of output terminals of the microphone. JIS C-550 specifies 50,00,50,400 and 600 ohms as standard. In the case of ECMs, the effective output resistance is determined mainly by the valve of load resistance. It can be made higher or lower by the value of load resistance with a corresponding change in sensitivity. The frequency response of a microphone is the data indicating which frequency range, from the lower to the higher range, the microphone has a certain sensitivity. In other words, it is the frequency range within whitch the microphone can receive sound. It is expressed as 50 Hz-5000 Hz.
Electret Condenser Microphones Specification List Omnidirectional Model No. KUF473 KUS03 KUR003 KUS003 KUF463 KUF453 KUB433 KUF433 KUB333 KUF333 KUB83 KUC353 KUC3 KUC403 Dimensions φ4 0.9 φ4.3 φ4.5 φ4.6 φ6.0 φ6. φ6.5 φ6.5 φ6. φ6. φ6.7 φ9.4 φ9.4 6.5 φ9.7 6.7 Mass (g) 0.04 0.07 0.08 0.08 0. 0. 0. 0. 0. 0.6 0.8 0.9 Sensitivity (db/pa) 44 Impedance (kω)..0..........0.0.0 Standard Power Supply (V DC).0.0.0.0.0.0.0.0.0.0.0 Current Consumption (ma) 0.8 0.8 0.8 Lead Wire PCB Solderless Solder Reflow Chip- Condenser Built-in available Chip- Condenser Soldered is available Unidirectional Model No. KUB83 KUB803 KUB893 Dimensions φ8 φ9.4 6.5 φ9.4 4.7 Mass (g) 0.7.0.0 Sensitivity (db/pa) 46 Impedance (kω).0.0.0 Standard Power Supply (V DC) Current Consumption (ma) 0.8 Lead Wire PCB Solderless Chip- Condenser Built-in available Chip- Condenser Soldered is available
Electret Condenser Microphones (Omnidirectional) KUF473 0.9.6 0.7 4 KUS03 Solder Reflow.3 0. φ.7 φ.8 φ4 φ0.7 KUR003 4.5.5 0.45.8-0.45 4.5.6 0.7 4
Electret Condenser Microphones (Omnidirectional) KUS003 Solder Reflow.6 0. φ.7 φ.8 φ4 φ0.7 KUF463.75 6.45 KUF453...9 6. 0.45.75 6.45
Electret Condenser Microphones (Omnidirectional) KUB433.5. 6.9.5 0.45 6.5.75 6.45 KUF433 6.5.9.9.5 0.45 6.5.75 6.45 KUB333..9.9 6 0.45 6..75.45
Electret Condenser Microphones (Omnidirectional) KUF333 6..9.9. 0.45 6. 6 KUB83 6.7.9 0.45.9.7 3 6.7.75 6.45 KUC353 9.4 0.4.54 9.4
Electret Condenser Microphones (Omnidirectional) KUC3 6.5 9.4 9.4 6.5 0.4.54 KUC403 6.7 9.7 0.4.54 9.7 6.7
Electret Condenser Microphones (Unidirectional) KUB83.9 8.35 0.45.5 8 KUB803 9.4 6.5 KUB893 4.7 9.4
Rubber Holder for Electret Condenser Microphones 7 3 6.5 7 8 9..8 8.5 9 6 9. 7 4 7.5 9.5 5.8 8 5 9. 3 6.4 KCU078 KCU08 4.3 5 KCU079 6.3 KCU07 4.7 3.5 5 5.9 8.9 KCU085
Specification Microphones Model No. HHM767 HHM758 HHM763 KHM87 HHM886 HHM896 ECM Directivility Non directional Uni directional Impedance (Ω).K K K K K K Sensitivility (db/pa) 4 SN SN Ratio (db) 55 55 55 56 55 36 Maximum Input S.P.L (db) 00 00 00 0 00 00 Cord Plug 3.5DIA Poles Mass (g) 0 7 3.5 53
Microphone HHM767 8.5 3.5 7.5 Plug : JIS C 6560 HHM758 8 36.7.5 R9 6 Plug : JIS C 6560 HHM763 40.4 0 8.6.5 40 Plug : JIS C 6560
Microphones KHM87 4 3 4 9 3.5 4 9.9 3 8.5 Plug : JIS C 6560 HHM886 4 7 3.5.9 6.4 4 7 Plug : JIS C 6560 HHM896 4 6 4 500 3.5 Plug : JIS C 6560