It carries a big stick

As a designer, I work in a fairly free-flowing environment and within that often comes a somewhat loud environment. To compensate and keep from getting distracted, I'm a big user of my iPod and iTunes (and various streaming websites). However, I was consistently (enough) forgetting my headphones between work and home, which made listening to music impossible (no speakers). Consequently, I found it harder to concentrate. Solution: a new pair of headphones to leave at work.

[ • but I already have 2 PAIRS • ]
True, I already own my Sennheiser PX 200 headphones and a pair of Sony ear buds. However, I've found ear buds to be a lot less effective at the noisier offices, and they also tend to hurt after a while. As for my 200's, I decided to leave them at home, where I had a better sound card to start with. So, I went looking for another pair of over-the-ear phones. My first choice was another pair of Sennheisers, since I liked them, although I wanted something a little less expensive. The PXC 150's were pretty well-rated and had a "NoiseGard" (noise-cancellation) feature that intrigued me, although I wasn't quite sure what they were it was exactly.

[ • the new SOUND • ]
When I finally got the phones, I immediately decided to try them out. And just as immediately, you'll find a tumor of a sort attached. Perhaps I didn't read closely enough, but I don't remember being told that I'd be hauling around an obelisk from "2001" with my headphones. It turns out that this growth is the NoiseGard device that these headphones have. Powered by 2 AAA batteries (which last a good amount of time), when you turn this stick on, it processes the ambient sound around you and boosts the sounds to counter it. This isn't simply increasing the volume but instead attempt to counter existing noise by using a reciprical sound wave that cancels that noise. As they say on their site: "The PXC 150 headphones with NoiseGard™ active noise cancelling technology let you enjoy music even in noisy environments by reducing up to 70% of unwanted noise." Supposedly it does this through two small microphones which record ambient noise and then create a sound wave that is 'phase-modified by 180 degrees compared to the noise'.

I'm a cynic by nature, so I was dubious of these claims. But there's not better proof than use, so I did. My first attempt left me very skeptical - sitting in a mostly silent room (I am usually one of the first in), the "noise cancellation" was little more than amplification accompanied by that background hiss audiophiles will remember from Dolby Noise Reduction days.

I was converted later, though. While not so good in quiet environments (which, to be honest, aren't really what this was designed for), when it was true "white noise" to deal with, the cancellation is surprisingly effective. My current office has an air vent running through it, which periodically (read: most of the day) has the heat running through it with a distinct hum. When I turned on the NoiseGard device, it did compensate pretty well for the noise and improved my sound.

And how is that sound? Pretty good, actually. Not up to the quality of my 200's but not bad. It struggles a bit at softer sounds/music, particularly those in lower tones. It also tends to amplify distortion a bit, so bad recordings will be a bit more so. But for a set of everyday headphones, they perform well for the price.

[ • here comes the BUT... • ]
BUT, there is 1 minor annoyance and 1 major annoyance. First, the minor - the size of the ear pads. They're pretty small so they won't be the most comfortable you've probably worn. One would think that noise-cancelling headphones would also want larger pads to aid in blocking outside sound, but that's not the case here. The pads are about 1 7/8" in diameter (compared to about 2.5" on the 200's). Not a huge thing but a gripe.

Much more annoying is the design of the NoiseGard 'stick'. At 5.25" (13.5cm) long and 3/4" (2.0cm) in diameter (about the thickness of a AA battery), it's pretty big and unwieldy. Worse, because of the cord length between the head phones and the 'stick', if you try to move too much, it falls off of your desk, yanking the head phones from your ears. I can't count the number of times this has happened. It comes with a clip, which might be fine on the train or walking around (although you'll look funny), but on a desk situation, it just doesn't work.

[ • tech SPECS • ]
Frequency Response » 15 - 21,000 Hz
Isolation » up to 24 dB
NoiseGard active noise reduction » less than 14dB (1000 Hz)
Nominal impedence » 300 ohms
Total Harmonic Distortion » 0.2%
Weight » 65g
Power » 2 AAA batteries
Accessories » two adapters for in-flight use storage pouch
Warranty » 2 years

[ • the final CUT • ]
These aren't bad head phones, and they do work in reducing the background noise at the office - so long as that background noise is a constant sound that it can cope with. The ear pads are a little small (a larger pad would increase the sound reduction), but the thing that really bothers me is that huge NoiseGard stick - it's obtrusive and annoying when you try to move around. If it weren't for that, I would give these headphones a better rating, but that 'feature' really is a major detriment.