By: Cliff PennockPrintablePaged


Not so very long ago, I bought the Sony MDR-NC11A Noise Canceling headphones. I travel by public transportation quite a bit and make a long plane trip at least once a year, so I thought that would warrant the purchase of such expensive headphones. I was so utterly disappointed with the Sony headphones (because the active noise cancellation simply didn't work and the sound quality was aweful) that I tossed them aside and bought the Sennheiser PXC 250 shortly thereafter.

Now the Sonys were earbud-style headphones which do block a lot of ambient noise by design, while the Sennheisers were earcup-headphones. So I really didn't expect them to work much better than the Sonys. Boy, was I ever wrong.


Before I continue, I'll try to briefly explain how active noise cancellation works.

Sound travels through the air as a waveform. As with all waves, when two of them meet, they will add up. So two identical but opposite waveforms will cancel each other out. The noise cancellation circuitry inside these kinds of headphones uses a tiny microphone to pick up the ambient sound, inverts it's waveform and adds it to whatever sound it's playing through its speakers, effectively cancelling out ambient sound reaching your ear directly.

Ok, forget what I just said - here's a drawing.




The Sennheiser PXC 250 retails at US $169.95 but can be found both in stores and online for considerably less. It comes with a carrying pouch, a plane adapter, a 3.5mm to 6.3mm jack adapter and a manual. The big cylindrical thing you see in the picture on the left is the headphones' cancellation circuitry. It has two wires coming out of it. One goes to the plug and one to the headset itself. It also holds two AAA batteries.

Like with the Sony headphones, I didn't need the plane adapter when I used them in flight. I still have no idea what these adapters are actually for. Maybe old airplanes have different kinds of in-seat connectors, I really wouldn't know since I like my planes to be younger than 25 years<sup>1)

1) Must... resist... urge.. to make... obvious.. "like my women"... joke...</sup>


The Sennheiser PXC 250 headphones can be folded so you can easily carry them around in its pouch while traveling. Unfolding and especially folding, can be a bit of a puzzle however. There's only one way to fold them properly and for some bizarre reason, you always get it wrong the first time you try. Look closely at the image to the right and you'll see why. The right arm goes over the left arm, but the ear cup of the right arm is under the left arm and also under the middle part. See what I mean?

Usually I'm not all too fond of small ear cups on headphones. I like them to completely cover my ears so they immediately block out a lot of ambient noise. Also, with bigger ear cups the pressure is on my head and not on my ear lobes. But the Sennheiser PXC 250 felt really comfortable, probably due to the thick cushions that are used on the ear cups as well as the padded head band. Plus, when I saw a few people on the airplane with noise canceling headphones with huge ear cups they did look, well, kinda ridiculous.

The headset itself is very light but the black tube that holds the cancellation circuitry is relatively heavy. It also holds two AAA batteries and that's probably the reason why. You absolutely need to clip this to your belt or a pocket or it will rip the headset off your head in no time.

The carrying pouch is very nice but also very big and unless you shop at the "Big & Tall", won't fit any of your pockets. This makes the PXC 250 true travel headphones since chances are you won't be using them for anything else.


If you've read the Sony MDR-NC11A review, you know that the first thing I did was hook the Sennheiser PXC 250 up to my A/V receiver. Unlike the Sony, these actually sounded pretty decent! Don't expect your head to be blown off by the bass, but the sound was pretty balanced throughout the low, mid and high range. Pretty impressive really for such a small headset.

Next on the list was of course to test its noise canceling capabilities. I wasn't in an airplane of course, but I figured I should be able to test it with the noise generated by the fans of my computer. I unplugged the headphones from my receiver and switched on the noise cancellation circuitry. Sometimes you do things that make you go "oh crap". This was one such moment. At first I thought that I had somehow shorted something by switching on the headphones because I actually thought my computer had switched itself off. I then realized it was still on, but the headphones almost completely canceled out its noise! When I tried it while playing music, I noticed switching on the noise cancellation also caused the volume to increase, probably due to some amplifier being thrown into the equation.

A few days later I was able to test the Sennheiser on a bus and again it was able to cancel out the noise coming from the bus engine almost completely. Last summer I was finally able to test them on an airplane - with the same convincing results. Be aware though that noise cancellation is mainly aimed at low frequency noise like those coming from plane-, train- and automobile engines - so don't expect to be wrapped inside a quiet, soundless bubble. You can still hear people and other nuisances noises around you. But the Sennheiser's noise canceling capabilites are really very, very good.


I use the Sennheiser PXC 250 mainly for listening to music on my PDA and on my computer. I love the fact it's able to bring the noise coming from my computer down to a minimum so I can hear the music in its full dynamic range. And even though I travel quite a bit by bus and by train, I hardly ever take them with me because they really are slightly too big to carry around when you are not using them. If you don't carry a briefcase around, then you really have no place to carry them around in. Next time I go on a plane trip however, they will most certainly be part of my carry-on luggage. That is, if by that time you are still allowed to carry on anything at all...

Noise cancellation is very good and sound quality is more than decent, as long as you don't expect them to give you studio quality sound. They excel in what they are meant for - nothing more, nothing less. And for a street price of between US $100.00 - 130.00, and if you travel by plane quite a bit, then they are really a great value for the money.

The good Comfortable, light and small headset Cushioned ear cups and padded head band Foldable design More than decent sound quality Impressive noise cancelling abilities The not-so-good Tube that holds noise cancellation circuitry relatively heavy Too big to actually carry around

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