The Koss QZ99 are passive noise cancelling headphones. The QZ99 model are mid-range in the QZ noise cancelling product line, both in price and in technical specifications. For a higher end product, try the QZ50 or the QZ2000. Designed to reduce the impact of environmental noise, these headphones use a processor to actively reduce low frequency repetitive noise. The headband goes behind the head and has closed ear cushions to reduce ambient noise. The headphones come with a lifetime, no questions asked warranty.
- Frequency Response is 40 - 20,000 Hz
- Impedance is 60 ohms
- Sensitivity is 102db SPL/1mW
- Distortion is
- Cord is 8 feet long, straight with single entry
- Lifetime Warranty
- Passive noise canceling through fit of cushions around the ear