The Altec Model 659A
cardioid moving coil microphone
The Altec 659A Professional Cardioid Microphone was developed for application in equalized sound systems that use the Altec Acousta-Voicing® process or in any sound system where a microphone with exceptional smooth and uniform response characteristics are required. Unusually smooth, the 659A achieves a high level of microphone performance, incorporating all the advanced engineering benefits of dual dynamic moving coil units. These dual cartridges divide the low and high frequency bands of the audio spectrum for improved frequency response and reduced proximity effect. The individual response curve of each 659A microphone is charted on a precision servo-driven recorder with the microphone operating in an anechoic chamber. This curve is supplied with its respective microphone.
The Altec 659A microphone has a nominal output impedance of 200 ohms for operation with low impedance input equipment. The high sensitivity of −53 dBm/10 dynes/cm² provides an increased signal-to-noise ratio in many situations. Average front-to-back discrimination is 20 dB. The diaphragms are rugged and durable; highly resistant to the effects of shock, blast or corrosive fumes and are able to withstand wide humidity and temperature variations. A built-in hum-bucking coil provides superior hum rejection. The 659A microphone has a standard three-pin XLR-type connector that allows most existing studio cable assemblies to be pugged into the connector. It is supplied with a cable set consisting of 25 feet of two-conductor shielded cable with a mating XLR-3 type connector on each end.
- Type: Dual dynamic moving coil, cardioid
- Frequency Response: 40 to 16,000 Hz
- Impedance: 200 ohms, nominal
- Output Level: −53 dBm (Reference: 10 dynes/cm²)
- Average Discrimination: 20 dB (front to back)
- Pickup Pattern: Cardioid
- Hum: less than −120 dB (Reference: 10−3 Gauss)
- Dimensions (excluding cable and plug): 1.6'' maximum diameter × 713⁄16'' long
- Weight (excluding cable and plug): 10 ounces
- Finish: Matte black and satin nickel
- Mounting: Supplied with an Altec slip-on adapter fitted with standard 5⁄8''-27 threads.
Swivel mounting permits proper positioning
Text and illustrations are from the Altec Sound Products Division data sheet AL-1735-1.