Koss Qz77 Noise Canceling Earbud QZ77_6

This item is brand-new, factory sealed.

The qz77 stereophone features both active noise reduction (anr) and passive noise reduction (pnr) technology which eliminate harmful and unwanted noise while still providing the ultimate in stereo sound. For years we have been striving to improve on the sound and portability of noise reduction products. The koss qz77 provides maximum noise reduction in a compact design. The anr technology utilizes tiny microphones embedded in the ear piece. These microphones sample the surrounding low-frequency noise and transmit information about those undesirable sounds to a processing circuit. The processing circuit, in turn, generates mirror image "anti-waves" that are 180 degrees out of phase and relays those anti-waves back to the stereophone. When the offending sound waves encounter the waves generated by the qz77, the two counteract each other at the wearers ear. The offending hum and buzz is reduced and a peaceful listening environment is created where once there was noise. Low frequency noise below 1000 hz, such as jet, bus or automotive engines, is reduced by an average of 10 db. Noise reduction is even greater for noise below 200 hz, offering a 15 db of protection against low frequency noise. Designed after another popular koss model, the plug, the stereo earbud features a dynamic element that is positioned just outside the ear. The element is connected to a tubular port structure that is inserted on a soft expandable cushion into the ear canal. Soft foam "memory" cushions expand for a custom fit to improve isolation and enhance deep bass and treble clarity. Utilizing the fit and mechanical design of the headphone to reduce noise is known as passive noise reduction (pnr). While the anr circuit reduces low frequency noise, the pnr reduces high and mid frequencies so music and voice can be heard in absolute clarity. Double noise reduction and maximum sound performance all in one complete product. The qz77 utilizes (1) "aaa" battery. frequency response= 10-20,000 hz impedance =16 ohms sensitivity =110 db spl/1mw distortion= <0.3% cord =straight, dual entry, 4ft