Date: March 3, 2008
Author(s): Rory Buszka
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.
The AblePlanet Clear Harmony NC1000CH headphones come in a gorgeous black and blue box that’s got plenty of bright images and clear, readable text. The retail packaging of the Clear Harmony headphones is extremely well-done, tastefully blending colors, textures, and finishes to create a positive impression of the product contained inside. These are AblePlanet’s flagship headphones, so it’s clear that they’ve put extra effort into the exterior packaging.
Inside the outer package (which is really just a thin cardboard sleeve) is another, sturdier white cardboard box. The Clear Harmony headphones themselves are contained within a padded carrying case, which also features a separate pouch for cables and connector accessories.
Here’s what comes with the Clear Harmony headphones: You get the headphones themselves, a detachable 4′ cable with an in-line volume control, a 35mm-to-1/4″ plug adapter, and an airline adapter, all with gold-plated contacts. You also get a set of batteries, as well as a quick-start guide and an instruction manual.
The Clear Harmony headphones feature clean, modern styling that’s aesthetically appealing. Their design closely mirrors the design of the well-known Bose QuietComfort headphones, to an almost startling degree – though the two are not look-alikes. They’re fairly lightweight, with my reference headphones (which are themselves fairly light) almost imperceptibly heavier.
Next, let’s take a closer look at the features of the AblePlanet Clear Harmony NC1000CH headphones.
AblePlanet’s Clear Harmony NC1000CH headphones blend a variety of traditional headphone, noise-canceling, and sonic enhancement technologies to improve upon the experience provided by traditional consumer headphones. Here’s an in-depth look at the features.
The AblePlanet Clear Harmony NC1000CH headphones feature a circumaural design, which simply means that they enclose the ear completely within the earcup, instead of sitting directly on it, or lodging inside the ear canal. Each earcup seals against your head with a soft, leather-wrapped pad, with a third leather-wrapped pad at the top of the headband. The headband features adjustable-length extensions, to accommodate a wide range of head sizes.
The processing circuitry and self-amplification for the Clear Harmony NC1000CH headphones is located in the left earcup, as indicated by the presence of a battery door. The Clear Harmony NC1000CH headphones take two ‘AAA’ batteries, and provide 30mW of self-amplification, in addition to the built-in noise-cancellation and “LINX AUDIO” processing.
The Clear Harmony range of headphones features AblePlanet’s proprietary “LINX AUDIO” processing, which generates higher-frequency harmonics throughout the frequency spectrum. Using higher harmonics to augment the bass range is a common tactic, but LINX AUDIO processing adds these harmonics to all frequencies, to create a richer and more “lively” sound.
On their web site, AblePlanet trumpets CES “Innovations” awards for LINX AUDIO products for three years running. Originally developed for the company’s range of assistive-listening products, the company is now applying LINX AUDIO technology to audio products of all types, including the Clear Harmony range of headphones.
One thing to note, however, is that ordinary loudspeakers also have a habit of adding their own upper harmonics when being driven to distorted levels, so the effect of adding these harmonics purposefully is essentially like replicating the effects of loudspeaker distortion, something that’s difficult to justify if high fidelity to the original signal is the goal.
Still, added distortion products can have the effect of greater apparent loudness, without actually increasing output levels. I’ll comment later on how well LINX audio works, in the ‘listening testing’ portion of the article.
The Clear Harmony NC1000CH headphones also feature microphones in each earcup that are part of the headphones’ active noise canceling system. This system picks up incident noise, and produces an inverse correction signal, which is then sent to the corresponding driver in the headphones, left or right. The result is that the overall level of infiltrating noise perceived by your ears is greatly reduced. Again, I’ll comment more on how well this feature performs in the ‘testing’ portion of the article.
To test the Clear Harmony NC1000CH headphones, I listened to a broad variety of music and gaming program, including music from my broad collection – which spans the rock, pop, soundtrack, and jazz genres. All program for this review was served from my ‘reference’ PC, which uses a high-quality ASUS Xonar D2 sound card, and stored in the form of FLAC and 192/KBps WMA files.
The reference PC’s cooling system is microprocessor-controlled by an MCubed T-Balancer fan controller, to minimize background noise. All critical listening was conducted with a fresh set of batteries.
To test the Clear Harmony headphones with music, I started out with Train’s Drops of Jupiter album. In the album’s title track, the piano theme should come through clearly, but the Clear Harmony headphones began to lean toward a warmer, almost congested tonal character, with the upper ranges being slightly overpowered by an overenthusiastic midbass range. They also exhibited a slight hollow character in the upper midrange.
The internal circuitry of the Clear Harmony headphones continues to pass unprocessed signal even with the switch in the ‘off’ position, though with the switch off, the headphones were barely listenable – they sounded distinctly more muffled and midbass-heavy, though the overall sensitivity was lowered.
With the switch on, and LINX AUDIO processing enabled, the sound was brighter, though it seemed like the additional upper harmonics added by LINX AUDIO simply compensate for the overly warm character of the headphones themselves. Switching the headphones on also resulted in more big, thudding bass.
In “It’s About You”, there’s a particularly airy acoustic guitar solo, but with the Clear Harmony headphones, this solo was a little lacking in its characteristic spaciousness and ‘bite’, though the sound was rich and full.
Next, I put in Anberlin’s latest studio release, Cities. The album’s opening track, “Godspeed”, began to show what these headphones are good for. The slightly rolled-off top end served to take a little of the edge off the electric guitars and cymbals, while the kick drum and low tom were rendered with frightening slam and authority.
However, I began to miss the extra top-end sparkle in the next track, “Adelaide”. On the acoustic track “The Unwinding Cable Car”, the acoustic guitars sounded clean and full, but were overpowered by the ‘cupped’ sound imparted to the vocals.
Overall, the sound of the Clear Harmony NC1000CH is barely ‘passable’ by audiophile standards, but by typical consumer expectations, the extremely powerful bottom end and reasonably clear upper midrange and lower treble may be appealing to some. However, the Clear Harmony NC1000CH headphones are easily outpaced by my reference Beyerdynamic DT 770 in treble extension, as well as the retrieval of fine detail.
Gamers may have little use for these headphones, because they do not have an integral microphone. However, gaming is still a great test of headphones’ positional audio capabilities, so I fired up a round of Valve’s Portal to test that aspect of their performance.
The Clear Harmony NC1000CH headphones handled themselves well for this test, proving themselves capable tracking moving sound sources in space. While it wasn’t the most spacious, precise presentation I’ve ever been treated to (that honor goes to the previously-reviewed Ultrasone HFI-700, these headphones are plenty useful for gaming – especially when you need to block out the noise of the competition.
To put these headphones’ noise cancellation capabilities to the test, I enlisted a variety of noise sources. My lab shares its space with a small gas furnace, which these headphones easily managed to block out, though they couldn’t quite eliminate the voice of a person speaking to me a few feet away. I found this was generally the case with a variety of noise sources – transient sounds like a door slamming or a sound system playing in the same room couldn’t be blocked out, but engine noises from passing cars were dulled considerably.
To test this further, I unplugged the headphones and took them for a walk outside. As before, the engine noise of passing cars and nearby heavy machinery was well-isolated, but other noises still infiltrated. With program material playing, however, any noise that managed to make it inside the earcup was attenuated to a point where it was no longer a disturbance, and only audible during silences. One point of concern, however: With the noise-cancellation activated, the headphones produced a barely-audible electronic hiss.
One place where the AblePlanet Clear Harmony headphones excel is in the area of listener comfort, with the foam-filled leather ear cushions staying easily in place while only exerting minimal pressure on the head. I didn’t forget I was wearing them, and they weren’t quite as comfortable as my reference headphones, but they were definitely wearable, and I found that long listening sessions weren’t a problem at all.
One nit to pick, however – the ear cups aren’t particularly large, only large enough to encircle the ear. The earcups on my reference Beyers felt positively roomy by comparison.
When Nate highly recommended the AblePlanet Clear Harmony headphones to me back in January, it was based on a cursory listen at AblePlanet’s CES booth. And these headphones are delightful in many ways – they’re light, very comfortable, and provide rich, satisfying sound, with fairly good external noise isolation when compared to headphones without active noise cancellation.
Their noise cancellation proved to be more than adequate in most cases, though to say that the built-in noise canceling feature entombs you in a cocoon of silence would be an overstatement.
For casual music listening, the Clear Harmony headphones work well, but they wouldn’t be my choice for a reference headphone, or for use in professional audio situations. These headphones can sound fine for music listening, and their “LINX AUDIO” processing imparts a character to the sound that many consumers may find appealing. However, at their asking price, you can treat yourself to a true ‘audiophile’ headphone with decent isolation like the Ultrasone HFI-700, and still have enough left over to buy a couple CDs.
With that in mind, I’m awarding the Clear Harmony NC1000CH headphones a Techgage score of 7. When compared to other noise cancellation headphones, they’re significantly more expensive than alternatives from famous makers like Sony, Philips, and JVC. Furthermore, it’s possible to do better for less cash if you’re willing to give up on the noise cancellation functionality. If you do choose to purchase these headphones, you likely won’t regret the decision, but eventually you’ll find yourself simply wanting more.
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