Some helmets offer a "passive" reduction, it is a sound insulation of the helmet ("closed helmet") which reduces a few decibels the surrounding noise. Besides, if the NC1 is not strictly speaking a closed helmet, earphones well flexible coating are pressed on the ears (loosely, which is significant) and therefore offer a certain degree of passive noise reduction .
The active reduction has nothing to do: in this case, the device uses the headset mics to capture the audio environment, and cancel that wave cancellation by pollution (headphones add to the music of the waves opposed to interference waves, it is supposed to hear only music and nothing else.) Philips and claims to have built 4 microphones in his NC1 to perfect the technique.
For this to work, the helmet has its own internal battery to power the electronic wave cancellation. Apparently it is also there to amplify the volume of the headphones.
Anyway, this headset is very lightweight, collapsible, excellent build quality and finish. It comes in a semi-rigid shell with a cable / headset (removable), an airplane adapter, micro USB cable for charging.
This helmet is proving very comfortable, wearable and slightly isolated. The sound quality is good, even very good I would say to a "nomadic" helmet - but at this price, there are also stereo headsets salon that can make him shade by offering a clearer sound, more accurate. It is hoped that the active noise reduction will make the difference, even if a stereo headset is generally much larger and often includes a microphone with call answer button, as is the case here.
Once the active reduction starting (via a small button on the left ear), which brand is the free increase in volume. I almost believed in the beginning that was the only difference, apart from a very noticeable background noise during white ... before you notice that the sound seemed as quite different, even a little deformed, once the volume back down to its normal level. Not very convincing. But the most disappointing thing is that I have no felt that the surrounding noise was reduced! This runs counter to the interest of the system, because a closed helmet is just as well, without battery and background noise. By public transport at home (vacuuming ...), I have found no benefit to activate the active noise reduction system.
There are excellent at Philips Fidelio, it is also good but the active system is simply uninteresting.
