by Rory Buszka on March 3, 2008 in Speakers/Headphones
When we met AblePlanet at CES, their Clear Harmony noise canceling headphones really caught our attention. Their built-in noise canceling circuitry is intended to reduce the infiltration of ambient noise, but can they stack up sonically against some serious competition within their price bracket?
At CES this year, Nate Marion visited AblePlanet’s booth, and had plenty of complementary things to say about the company’s Clear Harmony headphones, which blend the company’s “Linx Audio” sonic enhancement DSP processing with active noise-canceling technology.
The company offers a complete line of headphones and headsets for music listening, gaming, and telephony. Upon the CES team’s return, Nate suggested that I should take a set of their headphones for a spin, and Able Planet happily obliged us, sending along a set of their top-end Clear Harmony NC1000CH headphones for evaluation.
So, what is active noise cancellation, and how does it work? Quite simply, noise-canceling headphones have an external microphone, which picks up any exterior noise. This signal is flipped or reversed, and then fed into the headphone drivers. The result is that the headphone drivers essentially oppose any incident noise, and the net result is that the incident external noise never makes it to your eardrum.
That technique works best when a separate microphone is used for each ear, and the microphones are located as close to the headphone transducer itself as possible, so most noise-canceling headphones use microphones placed in the ear cups themselves.
Of course, a lot of noise infiltration can be prevented through careful ear cup and padding design, and many higher-end headphones already isolate well without noise-canceling systems. There’s a notable difference at lower frequencies, however, where it’s more difficult to prevent noise infiltration simply through passive isolation. At these lower frequencies, noise-canceling headphones have a clear advantage when it comes to blocking external noise.
There’s one distinct drawback to active noise cancellation, however – its cost. Exterior microphones and digital signal processing circuitry aren’t cheap, and that’s money that could be better spent on higher-quality materials, better drivers, et cetera. In this review, I’ll compare the AblePlanet Clear Harmony NC1000CH headphones to my slightly less-expensive $250 reference Beyerdynamic DT 770 circumaural headphones (without active noise cancellation), and we’ll see if the results are worth the trade offs.