First off, we can talk a little about the durability versus price, and what these headphones are intended to do. They are traveler headphones. If you've ever been on a bus, or an aeroplane, or a train, and you wanted to block out the ambient noise, hear music, but not disturb other passengers, these are your ticket. They're compact, they fit into a nice little case. They seal out noise, they don't bleed sound nearly at all into the environment, and their sound quality is quite decent (with exceptionally good bass for a headphone). If you travel a lot, these headphones are worth the $300 price tag. They simply are. If there's a warranty however, you might want to get it. These headphones ARE made out of plastic, and even though plastic is light, and decently durable. It is definitely not up to the many, many odd and rapid kinetic motions that make up your average hectic travel plan. The plastics will break over time. They also just... feel sort of cheap. You pay your $300 and whip out these headphones that if you just had somebody feel, they'd think they came from the local Radio Shack for $50.

Secondly, sound. How do these things actually reproduce audio? Well... quite nicely, thanks. No matter what you do, they will always have the "head in a can" feel of a confined air-space. There is simply nothing they can do about it and make a noise canceling headphone. To this end, they lack the very vibrant spatial imaging and smooth flow of sound that you may get from open headphones or speakers. Another thing is that, due to the process by which the active noise canceling works (see below). There is always a negative signal being layered into the music, so it is simply not as pure. These issues aside, it's good, it's quite good. Most people will be blown away. They've a deep and powerful bass, a nice though confined high end, and slightly warm mids.

How it works: The science of sound is very, very simple. In a nutshell, any object moving in a liquid will move that liquid. Moving liquids (in this case, air) is detected by humans in a variety of ways. When air moves very rapidly in 'pulses' or 'waves', we humans detect that because the air is vibrating our eardrums. The goal of the Bose QC2s is to block the outside air and the sound pulses it is carrying as much as possible. The headphones attempt to keep a static air bubble inside their cup. They succeed, to some extent. But sound will still get in, albeit, deafened. To enhance this noise canceling effect, Bose uses a system called Active Noise Cancellation. Basically, it mounts a microphone on the outside of each of the headphones. Every instant of time the headphones are turned on, that mic is recording the outside noises of that particular ear, it is then taking that noise, feeding it through a computer, which inverts the phase of the noise (makes sort of an opposite noise) and plays the inverted noise back through the headphones. This is designed to 'dampen' the effect of noise, which it does. However it does also mix a signal in with the music, which can and does lower it's effective accuracy. It is designed to allow sudden and important noises, like distinct voices and crashes of things falling and whatnot, through. Therefore you will never be totally oblivious (but you can pretend you are).

Then there are the little things. The headphones are a little small for the big-eared among us. They do require themselves to be fully circumaural. There is a pressure difference when they are attached and turned on that can be uncomfortable and even cause headaches. They have very nice and soft earpads. The L-shaped 1/4th inch minijack is a nice touch. The battery is sort of annoying, it doesn't go out very often at all, and is fairly easy to replace, but... still, the thought that your headphones must be turned on and off and are running on a battery can be a little irking. The cable can be removed from the headphones and they can be worn as they are for simply the sound cancelling effect. There are two amp settings, High and Low. One will waste battery faster but sounds bright and louder, the other is more conservative, but also somewhat less interesting to hear. Also, as an added bonus, the cable only attaches to one side, this making taking them off and putting them on much easier, and reduces cable clutter.

These are the traveller headphones. No exceptions. If you just want good sounding headphones, you can get much better deals. You are paying an immense premium for the active noise cancellation and the Bose name. Better sounding headphones are easy to get, as are much cheaper noise cancelling ones. I have not tested the others therefore I cannot say how much they differ. You may do well to look at some of the other options before plopping down $300 when another $100 pair may do you fine. Always explore and research before you buy.

• They cancel noise, very very well.
• They sound fairly good.
• They can be driven off things as small as a walkman to comfortable volumes.
• They have a convenient L-shaped 1/8th inch stereo plug (as opposed to the straight ones which are ill suited to portably uses).
• The cable detaches from the headphones, furthermore it only attaches to one of the two phones keeping cable tangle to a minimum.

• They cost $300 USD list price. Expensive? You betcha. Worth it? Perhaps.
• They are made of plastic. Cheap? Yup. Durable? Not really.
• Bose doesn't release statistics for their products so there isn't an easy way to compare them to anything.
• They run on batteries.
• Did I mention that they're made of plastic?
• Pressure seal to your head.

• Build Quality/Feel: 4/10
  
• Audio Reproduction: 7/10
  
• Noise Cancellation: 9/10
• Overall (standard use): 6/10
  
• Overall (travel use): 9/10