Frankly, I think these new Bose headphones put the QC-2 to shame!
I've owned both QC-2 and QC-3 headphones for for a couple years, and their predecessor before that. My home is in a rural area that over time has become increasingly noisy with automobile traffic, chain saws, weed whackers, air travel, boats, etc, so have become a great fan of noise-cancelling headphones, which for me provide respite against all this sonic assault.
When I read the specs of the QC-15, I thought, if these are an improvement over the QC-2, I'll have to try them. This in the face of feeling sheepish about blowing another $300 for what I feared might be a trivial difference in quality.
I needn't have worried. When I turned on the QC-15, it was like shutting off the world. The loud rushing sound emitted by the air filter running 15 feet away became nearly inaudible, the low rumble of distant boat, air, and automobile traffic disappeared altogether. The background hiss generated by the QC-15 is noticeably quieter than the QC-2, and the noise cancellation, as Bose advertises, covers much more of the audio range. My QC-2 headset doesn't do nearly as good job at cancelling the white noise from the air filter as the QC-15, for example.
As for sound quality, the QC-15, to my ear, has better response in the deep bass, from 25-35 hz, and les resonance in the 80-150 hz range. The bass is generally tighter as well. If you're used to the mild boominess of the QC-2, as I was, it might take you a bit of listening to appreciate the difference. In higher frequency ranges, the QC-15 seems comparable to the QC-2. My 64 year-old ears cut off arount 8 khz, so I'd defer to the judgement of younger listeners in this area.
All-in-all, I'm very happy with the improvements manifest in this new version of the Bose headphones and feel that even at $300 they're well worth it.
The only negative criticism I can make so-far is that the headphones emit a rather loud click when you turn them on, compared to the QC-2. This is not a big deal- I just make sure to throw the ON switch before putting the phones on my head.
By the way, many users of Bose (and other) noise-cancelling headphones complain , sometimes bitterly, about he sensation of "ear pressure" when the noise-cancelletion is activated. This is an illusion that arises because actual pressure on un-equalized eardrums (as when climbing or descending in an aircraft) has the effect of reducing the low frequency response of the eardrums. That loss of low-frequency sensitivity is read by the brain as pressure, which, in the case of altitude change, it actually is. Noise cancelling headphones drastically attenuate ambient low frequency sounds, many of which we register unconsciously.
The brain interprets this as pressure on the eardrum, even though this is not actually the case. The sensation of pressure produced by noise cancellation is actually an indication of just how much very low frequency background sound we tolerate under normal circumstances. Research indicates that such low-frequency sounds can actually be a source of low-grade anxiety. Hence you may find that these headphones attenuate your nagging anxiety along with the background rumble generated by the pervasive combustion of fossil fuel all around us.
