The Electro-Voice Model 643
Cardiline dynamic cardioid microphone
Description and Applications
Designed for specialized and extended long-range pickup, the Model 643 Cardiline® microphone combines the best characteristics of cardioid and distributed front-opening designs. This microphone provides a cardioid pickup pattern up to 100 cps and is highly directional over the balance of its range. (See Figure 4) The microphone includes integral two-position low-frequency tilt-down and cut-off filters for suppression of room reverberation and retention of presence.
The microphone comes equipped with a sharp cut-off, high-pass filter with high attenuation of frequencies below 100 cps, located at the rear of the microphone, under the bar. It is important that the input impedance of the filter be adjusted to equal the microphone’s impedance. An external switch is provided for this purpose. The “OFF” position switches the microphone straight through.
- Element: Dynamic
- Output Level: –48 dB (1 mw/10 dynes)
- Frequency Response: Flat from 30 to 10,000 cps or choice of 5 or 10 dB frequency reduction steps with external screwdriver slot adjustment. Position F = Flat, 1 = First Position Roll-off, 2 = Second Position Roll-off. (See Figure 3) Sharp cut-off high-pass filter provided to eliminate frequencies below 100 cps with use of external switch
- Polar Pattern: Cardioid-line
- Diaphragm: Acoustalloy®
- Impedances Available: 50, 150, 250 ohms
- Switches: Low-frequency reduction
- Cable Connector: Cannon UA-3-11
- Case and Frame Material: Aluminum
- Finish: Gray Metalustre
- Net Weight: 12 pounds
- Hum Pickup Level: –125 dB (ref 001 gauss field)
All text is from the Electro-Voice Model 643 Engineering Data sheet, which is available below for download.
Figure 1 — Dimensions
Figure 2 — Wiring diagram of the Model 643 microphone
Figure 3 — Frequency response
Figure 4 — Polar response
Figure 5 — Frequency response with Model 513 Filter engaged
Figure 6 — Wiring diagram of the Model 513 Filter