Summary: I use a diesel tractor to cut lawns and having the head phones to drown out noise while enjoying an audio of my choice rather than hearing the the loud noise of the tractor. I hear a fan noise which is considerably less nosey without.
Pros: The head phones are comfortable even when cutting a field in a hot and humid environment.
Cons: Cost is high but the payback is in meeting and exceeding my expectations.
Summary: the noise reduction system works well. However, that comes at the cost of headphones that fit tight over your ears. On a long flight, after the 2nd movie I watched, my ears and my head were hurting. Not to mention how sweaty your ears get from being completely sealed off from air.
Summary: I have the opportunity to study at work so I needed some noise-cancelling headphones to block out the ambient noise of my coworkers. I work in a conex (container) that is about 7 feet wide and 40 feet long with military grade environmental control units blasting constantly and 2-6 people in the same...
Pros: Well built, look great, mostly effective with average office noise and even above average noise, comfortable
Cons: Not wireless, no bluetooth, larger size, does not eliminate all noise, turning your head away/toward a sound source may lead to nausea or dizzyness.
Summary: I have a couple issues with these but I haven't given up yet. They are large and bulky and I don't look forward to taking them on a plane. They were also quite expensive. The noise reduction doesn't drown out my neighbor and the rock tumbler he uses for a lawn mower.
Summary: I was very concerned about purchasing this set vs. a Bose. I've wanted a Bose for years, but the mechanical quality issues worried me. I'm very happy with this purchase. I just finished an 14,000 mile international flight and shared them with many people.
Summary: I have been using this PXC450 for more than 2-years, which replaced my Bose QC15. As other reviews mentioned, the sound quality of the PXC450 is clearly better than the Bose QC15. You can itentify more sounds in the sound track which you can't hear with the Bose (too heavy on bass).
Summary: The Sennheiser PXC 450 headphones arrived safely and well packaged - also very promptly. I found it a little odd that the english language portion of the manual was buried in the middle of a rather thick folded booklet.
Summary: Re the concerns with impedance, the high impendace does not imply the need to use a separate amplifier. The only certain consequence of the higher impedance is that the headphones will draw less power from the source, relative to a given volume setting at the source.