Sennheiser PXC 350:
The PXC 350 is a circumaural high-end travel headphone set with NoiseGard™ Advance technology for active attenuation of ambient noise.The PXC 350 enables an unprecedented sound experience for people on the move, thanks to its adaptive baffle damping in combination with the patented Duofol diaphragms, which prevent unwanted partial oscillation and thus guarantee a highly natural, lifelike sound quality.NoiseGard™ is an active noise compensation system which Sennheiser originally developed for use by pilots, who have to rely on good sound quality and efficient protection against ambient noise even in high-noise environments. NoiseGard™ actively compensates the noise, based on the physics principle of sound and counter-sound, which works as follows: tiny microphones pick up the low-frequency ambient noise in the vicinity of the user’s ear. Based on that noise interference, the NoiseGard™ electronic module calculates the required counter-sound wave with 180° phase inversion. The unwanted noise and the phase-inversed wave meet directly at the user’s ear where they virtually cancel each other out. The result is an effective reduction in ambient noise. The music is transmitted in the same high quality, so that even quiet passages can be enjoyed in noisy environments.The PXC 350 features the NoiseGard™ Advance technology. This technology is a further development of the filter functions used in the original NoiseGard™ system, and enables even better active attenuation of ambient noise of up to 85%. It is of course also possible to use these headphones passively, i.e. without NoiseGard™ and without batteries.