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Overview: The AKG K391 NC in-ear headphones are equipped with Active
Noise Cancellation through a small in-line module. The headphones also have an
in-line single-button remote/microphone to control your phone calls and music
playback. The headphones and accessories can be stored in the supplied soft
Active Noise Cancellation: Each ear bud contains a tiny microphone
that picks up ambient noise. This noise is then canceled by an exact, but
opposite, waveform. All you hear is the music or audio that comes from your
smartphone. The ANC function can be turned on or off via a switch on the in-line
Power Requirements: The Active Noise Cancellation function is powered
by a rechargeable battery located in the in-line module. The battery charges in
about 1-2 hours via USB through the supplied cable. A fully-charged battery
gives you approximately 35 hours of noise canceling performance.
Ear Buds: The K391 NC's ear buds have a closed back design to keep out
unwanted noise. They have an elegant brushed aluminum finish, and come
with three sizes of ear tips so you can achieve a good fit.
Cables: The headphones have a 44" cable from the ear buds to the Noise
Canceling module. Two different 19" cables are included for different smartphone
modules. The cables are made of 99.99% oxygen-free copper for best signal
transfer. An airline adapter (single female 3.5mm-to-dual male 3.5mm) is
included to allow you to use the headphones for in-flight entertainment.
Compatibility Note: The K391 NC headphones are compatible with the
majority of smartphone manufacturers. Most Apple, Samsung (from Galaxy S2), LG,
HTC, Sony, Motorola, and Blackberry models will use the cable with the silver
plugs. Some manufacturers, such as Nokia, require a different pin assignment, so
many of their models will use the cable with the black plugs. Not all
manufacturers provide support for the microphone and/or call answer button. Full
compatibility with the button is only guaranteed with Apple devices.
- Frequency Range: 12 Hz - 24 kHz
- Sensitivity: 107.5 dB SPL/V (passive); 115 dB SPL/V (active)
- Driver Impedance: 32 ohms
- Maximum Input Power: 500 mW