The Electro-Voice 660 and 660A dynamic supercardioid microphones
The Model 660 is finished in Satin chrome, while the Model 660A carries the non-reflecting gray finish. Other than that, technical specifications of both models are identical.
Description and Applications The Electro-Voice Model 660 is a rugged, supercardioid, dynamic microphone designed to provide reliable service in the many situations that directional microphones are required.
Nearly all directional microphones exhibit proximity effect (a boost in low frequency response) when used close to a sound source. The 660 does not because it utilizes the Electro-Voice patented Variable-D principle. Therefore the 660 will more accurately respond in those situations that demand the talker, singer or instrument be close to the microphone. The principle underlying close miking is that the sound pressure level at the microphone increases 6 dB each time the distance from the sound source is halved. Obviously the output level of the microphone then increases proportionately resulting in a louder sound system or better signal to noise on a recording. Close miking can also reduce the often undesirable effects of reverberation as well as provide an increased separation among competing sounds.
As a super-cardioid the 660 provides maximum rejection at 150 degrees rather than the 180 degrees of a cardioid. This assures greatest rejection in the horizontal plane when the microphone is tilted to its most natural position, 30 degrees from the horizontal (on a desk or floor stand). The polar response (sound source at varying angles to the microphone diaphragm) is exceptionally uniform with little or no off axis coloration. This is important because it means the microphone’s response in actual use will closely parallel the anechoic on-axis curve (see Fig. 1). Many cardioids have good on axis response, but radically different response at other angles meaning the microphone’s published curve (undoubtedly on axis, anechoic) is of little practical use.
The 660 uses the mechanical nesting concept of design providing a nearly solid mechanical structure that is highly resistant to damage from shock. The exclusive non-metallic Electro-Voice Acoustalloy diaphragm is virtually unaffected by extremes of atmospheric conditions. The case is made of pressure cast zinc with copper, nickel and chrome plating.
Frequency Response: 90 to 13,000 Hz (see Figure 1)
Polar Pattern: Super Cardioid (see Figure 2)
Impedance: 150 ohms/Hi-Z, selectable
Impedance Change: Rear of connector insert (see Figure 3)
Output Level, 150 Ohm Impedance: -56 dB (0 dB = 1 mW/10 dynes/square centimeter) High Impedance: -55.5 dB (0 dB = 1 volt/10 dynes/per square centimeter)
EIA Sensitivity Rating, 150 Ohm Impedance: -150 dB; High Impedance: -150.5 dB
Diaphragm: Electro-Voice Acoustalloy
Case Material: Pressure cast zinc
Dimensions: 165.1 mm (6.5 in) by 38.1 mm (1.5 in) maximum, tapered shank (See Figure 5)