Frequency response: 40-20,000 Hz
Impedance: 32 ohms
Sensitivity: 90 dB SPL/1mW
Battery time: Approx. 30 hours of continuous play using batteries. The headphones will work without batteries, but not feature noise canceling.
Sound: Noise canceling technology
Sound: Employs both passive and active noise reduction (ANR) technology
Structure: Fully collapsible
Structure: Extra-soft, padded headband
Headphones with soft vinyl closed ear cushions
Straight, single entry 4 foot cord
Limited Lifetime Warranty
Packing the one-two punch of passive and active noise reduction (ANR), the Koss Quiet Zone QZ PRO headphones are the noise cancelling headphones of choice for music lovers. Their comfort and collapsibility – not to mention sound quality – make them a favorite among travelers.
For passive noise reduction, the QZPRO feature soft vinyl, closed cushions, which create a tight seal around the ear and reduce ambient noise, all while retaining bass frequencies. Active noise cancellation circuitry – embedded into each QZPRO ear cup – uses tiny microphones that sample surrounding noise and transmit that information to a processing circuit, which then generates "anti-waves" to counteract the unwanted noise and create a peaceful listening environment. No need for noise cancellation? No problem. Turn it off with the flick of a switch.
Not only do the Koss QZPRO excel at noise cancellation and reduction, they deliver uncannily high quality sound. The dynamic element bears a full frequency response of 40-20,000 Hz, allowing these noise canceling headphones to boast deep bass and balanced midrange.
Koss Limited Lifetime Warranty
Each Koss product has a Limited Lifetime Warranty, which covers normal use by the initial user or purchaser of this particular Koss product. Koss hereby warrants only to the initial user or purchaser that this Koss product will be free of any defect in materials and workmanship for the life of the product.
This warranty does not apply to any INITIAL USER OR purchaser who allows this product to be used by multiple PERSONS. This warranty is the sole and exclusive warranty for this Koss product and is in lieu of all other warranties (express or implied), including any warranty of merchantability or fitness for a particular purpose.
The sole and exclusive remedies available to the initial user OR PURCHASER for any defects in materials or workmanship shall be the obligation of Koss, at its sole option, to either refund the purchase price of the Koss product, or repair or replace the non-functioning or defective Koss product provided it is returned to Koss in secure packaging together with a check for $9.00 ($10.00 Canadian) to our factory at 4129 N. Port Washington Ave, Milwaukee, WI 53212.
If purchased outside the U.S. contact the local Koss Authorized Dealer for details.
Koss reserves the right to replace any discontinued product with one of equal value. Koss shall not be liable for any loss, injury or damages to persons or property resulting from the use of this product or any failure of or defect in this product, nor shall Koss be liable to the initial user of this product or to any other person or entity for any general, special, direct, indirect, incidental, consequential, exemplary, punitive, or OTHER DAMAGES of any kind or nature whatsoever. The repair or replacement of any non-functioning or defective product or the refund of the purchase price, at Koss' option, shall constitute Koss' only liability to the initial user or purchaser, whether such liability is based on contract, tort, strict liability or otherwise. Some states may not allow the exclusion or limitation of damages set forth herein in which case the above language may not apply to you. This limited warranty gives you specific legal rights and you may also have other rights, which may vary among states or provinces. If usage of this Koss product violates the guidelines of this limited warranty, Koss will repair the product and charge the purchaser for the cost of company time and materials.
What does frequency response mean? (if applicable to your product)
The range of sound reproduced by the stereophone or speaker from the lowest bass to the highest frequency. The broader the frequency response range of a product, the greater highs and lows it can reproduce.
What does it mean when a product is amplified? (if applicable to your product)
An amplified product is one that operates on its own power supply (AC or batteries). This applies to certain computer, portable, and home speakers and stereo systems. Conversely, unamplified products must be connected to an amplified sound source in order to operate.
Why is it important that a stereophone or pair of speakers be magnetically shielded? (if applicable to your product)
If the magnets that power a pair of stereophones or speakers were not shielded, they could cause interference, a distorted picture or even data loss when used with a TV, VCR or computer. All Koss Stereophones and Speakers are magnetically shielded.
What is Active Noise Reduction (ANR) Technology? (if applicable to your product)
Active noise reduction technology in stereophones creates an invisible shield between the listener and the droning sounds of the world by stopping low frequency noise before it reaches the ears. Tiny microphones are embedded in the stereophone ear cups. These microphones read the surrounding low frequency noise and transmit information about those undesirable sounds to a processor in a pocket sized control case. The processor, in turn, generates mirror image anti-waves that are 180 degrees out of phase and relays those anti-waves back to the stereophones. When the offending sound waves encounter the waves generated by noise reduction technology, the two counteract each other at the wearer’s ear. The offending hum and buzz is reduced and a peaceful listening environment is created where once there was only noise. Lawn mowers, jet engines, crowded environments, vacuum cleaners, computer fans or any other low frequency noise below 1000 Hz can be reduced by an average of 10dB by Koss’ Noise Reduction Stereophone the Quiet Zone 2000. Quiet Zone noise reduction is even greater for noise below 200 Hz, offering at least 15dB of protection against low frequency noise.
Are Koss stereophones and computer speakers compatible with different types of computers? (if applicable to your product)
Yes. Koss stereophones and computer speakers will work with any computer that has a 3.5 mm headphone/speaker jack attached to its sound card or CD-ROM, regardless of whether it's a MAC or a PC.
How can I order replacement ear cushions for my Stereophones? (if applicable to your product)
Yes, replacement earcushions are available for most models.Please select the "find replacement ear cushions" link on the left navigation bar to find your model.
How is a dual volume control different from a balance control? (if applicable to your product)
A dual volume control incorporates volume control and balance control into one control. It allows the listener to adjust the sound level in either stereophone ear cup independently of each other. A balance control works in conjunction with a volume control to limit or increase the amount of sound that reaches a listener’s ear. A dual volume control is also a great feature for people with partial hearing loss in one or both ears.
What's a dual entry cord versus a single entry cord? (if applicable to your product)
A dual entry cord splits into a Y with each end attaching to an ear cup. A single entry cord attaches to the stereophone at one ear cup only for greater freedom of movement.
What are the advantages of a metal headband over a plastic one, or vice versa? (if applicable to your product)
It is mostly a matter of opinion. Each has their own benefits a metal headband is more durable over the long run while a plastic one offers greater comfort during extended listening. The preference is a personal one.
What does side-firing mean? (if applicable to your product)
Side-firing is a term used to describe ear-buds that go into the ear sideways, directing sound into the ear canal for improved bass response.
What is the benefit of a dual volume control? (if applicable to your product)
A dual volume control enables the listener to adjust the volume on each stereophone cup individually. This is a great feature for those listeners who are hearing impaired in one or both ears.
What is the difference between an open and a closed ear cup? (if applicable to your product)
An open ear cup provides a more hear-through, airy sound while a closed one delivers deeper bass response. Most commonly, a closed ear cup is paired with a closed (circumaural) vinyl or leatherette ear cushion for maximum isolation while listening and an open ear cup is paired with a foam ear cushion for greater sound transparency.
What is the difference between infrared and radio frequency (RF) cordless technology? (if applicable to your product)
Infrared is cordless technology that operates on a beam of infrared light transmitted from a transmitter connected to the sound source to the stereophone. Listeners must remain within the line of sight from the transmitter to the stereophones or the signal is broken. A remote control for a TV operates on infrared technology. Radio frequency, on the other hand, operates on a radio signal transmitted from a transmitter connected to the sound source to the stereophone. Listeners may move freely, in any direction out of sight of the transmitter, up to a designated amount of space. Neither technology is necessarily better than the other it is mostly a matter of personal choice. Infrared is generally less susceptible to interference than RF, while RF allows the listener to roam more freely throughout their home. When considering a cordless purchase, think about how you would use it. If you are more inclined to listen in one room only, the infrared unit offers a stronger signal with less interference. If you prefer greater freedom of movement, an RF unit will enable you to move about freely from room to room. Just as sound is subjective, so is how you choose to listen.
Who uses a balance control? (if applicable to your product)
Anyone who has partial hearing loss in one or both ears can use a balance control to adjust the balance of sound to either stereophone ear cup, customizing how the sound reaches their ears.