The Sony MDR-NC40 earphones look expensive. The unit is almost entirely black, with a subtle chrome trim. This gives the headset a sophisticated, adult appearance, which sets it apart from many competing sets. Priced at $99.99, however, these lightweight, supra-aural (on-ear) headphones offer terrific value for the money.
Sony MDR-NC40 Earcups Feel Similar to Bose
The construction of the ear cups is remarkably similar to that of the Bose supra-aural headphones. They are covered in black leather and padded with pressure-relieving urethane cushions. That combined with the seemingly nonexistent weight of the cups allows the user to wear them comfortably for hours at a time.
Features of Sony Noise Cancelling Headphones
The Sony MDR-NC40 uses active noise-canceling technology to reduce outside sound. A pair of tiny microphones (one outside ear cup) samples the outside noise. Then, the internal electronics automatically generate white noise at an equal but opposite frequency to cancel out the noise.
Sony advertises that the MDR-NC40 is capable of eliminating up to 80% of outside noise. However, the effectiveness depends upon the type of noise. It works best with low frequency background noise, like the sound of an air conditioner, or the low rumble heard in the passenger cabin of an airliner. According to Sony the active noise canceling system has a range between 50 and 1,500 Hz.
A single AAA battery powers the noise attenuation feature, and according to Sony, is rated to last for 40 hours. Many similar models require two or even three batteries. The battery is stored in a small inline dongle on the cord, instead of fitting inside the ear cups as on some models. This reduces the weight on the ears.
Unlike the more expensive Bose models, the headphones may also be used with the noise canceling switched off. They do sound a little flat when the noise canceling is off, but if your battery dies, or you just want to save power, it is very nice to have this option. Additionally, there is a "Monitor" button on the dongle that momentarily shuts off the noise attenuation, and allows one to hear outside noise if needed.
The MDR-NC40 is very compact and travels well. It weighs just 4.2 ounces. The ear cups fold inward; basically reducing its size by one half. It comes with a nice sturdy leather case that holds the headphones perfectly, and also has space for a spare battery and the included airline adaptor.
The Sound Quality of Sony MDR-NC40
The Sony MDR-NC40 headphones have a remarkably full, rich sound in all pitch ranges for a product in this price range. The unit was tested with pop music, as well as with classical, country, and opera. In each case the sound was superlative. True audiophiles will still prefer the more expensive offerings from Sennheiser or Bose, but for $100, one would be hard pressed to find a better sounding headset. For the more technically minded, according to Sony, the 30 mm drivers have a frequency response between 14 and 22,000Hz.
