User manual SENNHEISER HDC 451-1 PRODUCT SHEET

[. . . ] HDC451-1 Active Noise Cancellation Headphone · Lightweight (3. 9 oz) · Active noise cancellation -10dB · In-line battery pack HDC451-1: Active Noise Cancellation Portable Headphone Built for the purpose of reducing potentially damaging low frequencies, the HDC 451 incorporates tiny microphones that monitor the acoustic environment detecting frequencies between 400 and 1000 Hz. [. . . ] While wearing the Open-aire NoiseGardTM mobile, you are always addressable since the vocal frequency range is hardly affected by the noise compensation. The HDC 451 NoiseGard mobile, incorporates an in-line battery box that can easily be clipped to your clothing, proving ideal for portable applications, especially during travel by train, bus, airplane or as a passenger in an automobile. Not only is NoiseGard advantageous for the traveler, it is also appropriate in the work place where air conditioning noise, computer hums or typical large area office noise is present. Sennheiser's NoiseGard mobile HDC 451 is an ideal solution for today's increasingly noisy world. The HDC451-1 comes with a two year parts and labor warranty. SPECIFICATIONS Transducer Principle Frequency Response Impedance Distortion (THD) Nominal input voltage (AF) Attenuation Power Supply Open-Air®, Dynamic 20 Hz - 18, 000 Hz 270 Ohms 1% 94 dB 10 dB between 400 - 1000 Hz 2 x 1. 5 V "AA" cells (Alkaline) 2 x 1. 2 V "AA" cells (NiCd 600mA) Approx. 110 g (3. 9 oz. ) 1/8" mini stereo plug for audio signal Operating Time Headphone Caliper Pressure Weight Without Cable Connector SENNHEISER ELECTRONIC CORPORATION, ONE ENTERPRISE DRIVE, P. O. [. . . ] World Wide Web: http://www. sennheiserusa. com Manufacturing Plant: Am Labor 1, 30900 Wedemark, Germany HDC451-1 7/97 [. . . ]