Koss QZ900 Noise Cancelling Headphones

Koss' QZ900 is the latest addition to their Quiet Zone line and adds a new level of performance and comfort. The electronics package inside each QZ900 is designed to monitor outside noise received through specifically mounted microphones in each ear cup. Once this incoming noise can be analyzed, the Koss QZ900 circuit introduces a sound wave that is 180 degrees out of phase with the incoming signal. The result is what engineer's term "zero earth" at the point of the eardrum. This means that most low frequency distractions from an airplane, lawn mower, fan, or even the din of an office can de dramatically reduced.

The noise cancelling ability is so good in the new QZ900 that you'll find less need to turn up the volume and overdrive the tiny amplifier in your portable electronics. This means greater efficiency and less distortion. The QZ900 operates with or without its active noise cancelling circuit engaged. A handy removable cord features an in line volume control and one standard AAA battery provides approximately 50 hours of active noise cancellation.

Specifications:

• Frequency Response: 20Hz - 20kHz
• Impedance: 32 ohms
• Sensitivity: 100 dB SPL
• Cord: Straight, Single Entry, 4ft