I received my pair of M40s, and I'm not sure what to expect from the noise canceling. I've had other noise canceling headphones in the past (Bose, etc.) and there has been a noticeable difference when noise canceling is turned on (almost a white noise is present, and all low level background noise disappears). With the M40s I hear no noticeable difference, I've tried them with the TV on in the background, road noise, etc. and there is no noticeable difference between on and off. I returned one pair because of this issue, just received my replacement pair, and I've got the same issue. Is it possible I got two faulty pairs? Or is this just how they are supposed to work?
What's your experience? What do you hear when you turn the noise canceling on? I talked to a Klipsch product support rep and they said they are technically noise isolating and not noise canceling and work differently from what you'd get from other manufacturers, but they are marketing them as noise canceling, so I'm not sure if he was correct.