It actually works the same as ‘Motional Feedback’ in speakers. This can easily be seen in the frequency and distortion plots further down this article. Not only the unwanted outside noises are attenuated (by applied anti-sound) but also the reproduced audio is a LOT closer to the actual applied signal. When the headphone driver/acoustics itself ‘colours the sound’ or outside noises enter the cups the microphone + N.C. The microphone ‘measures’ the acoustical signal inside the cups and compares that to the applied music signal. This way the music signal IS now the ‘reference’ to which the N.C. The applied music signal is added to the ‘reference silence’. Instead of total silence we want to listen to music. This only works for lower frequencies because phase differences become a problem due to the speed of sound and the wavelengths of these frequencies. Of course this isn’t ‘perfect’ as only sounds near the microphone are compensated (for a big part). That’s what the Noise Cancelling circuitry inside ‘aims’ for. So if the microphone picks up sounds that should not be there the opposite signal is applied to the speaker. Audio is a very ‘slow’ signal for electronics.
#Bose quietcomfort 35 drivers driver
It then applies the ‘opposite’ signal to the driver in order to make the final result ‘silence’. The ‘inner microphone’ listens to what is ‘heard’ inside the cups and compares this to ‘silence’. The Noise Cancelling trick works as follows. There are also microphone(s) on the outside of the cups but these do nothing for the Noise cancelling and are solely there for taking/making calls. The microphone inside the cup ‘listens’ to ALL sounds in the ‘ear chamber’ and thus picks up the music playing AND the, attenuated by the pads and cups, outside noises as well. on.įortunately the Bose QC35-II is one of the best performing NC headphones in this specific area (low self noise in quiet passages). The better (read lowest noise) the microphone and microphone pre-amp are the less audible noise there will be with N.C. This is the reason/cause for the audible noise that can be heard during silence or very soft passages in most NC headphones. That (small electret) microphone signal is amplified. The way Noise Cancelling works is by using a microphone inside each cup. Beware when you want to buy this headphone and buy from official Bose dealers only. Warning: There are fake QC35-IImodels on the market. It basically is a QC35 with added functionality (action button) The noise cancelling function works quite well for blocking out low frequency noises such as hum from engines, computer fans, airco etc. The Bose QC35-II ( Quiet Comfort) is a noise cancelling headphone which is particularly suited for travelling by plains, trains and automobiles. The bigger the deviation the stronger the effect.īelow an aid to help determining the sound character of headphones with relation to the frequency response. Deviations in different severities at different frequency bands have an effect on the sound character. A horizontal line shows audible neutral response in the plots on this website. The shape of your head, bone structure, pad size, pad ‘softness, (compliance), hair or no hair and or wearing glasses may (drastically) change the frequency response of some headphones, so… your personal experience may differ substantially from these plots.įrequency response (tonal balance) is the most sound-determining aspect of headphones. This is described HERE in more detail.Ī ‘ horizontal‘ frequency response curve on the shown frequency response plots on this website thus indicates a perceived ‘flat’ tonal signature.ĪLL measurements are made with a good SEAL on a flatbed measurement rig. I do not use smoothing because some info about sound quality is lost when plots are smoothed.Īside from a small correction of the microphone itself also some correction in the lowest frequencies is applied to the plots to compensate for the perceived loss of bass when using headphones. Most measurement sites have some smoothing applied which ‘irons flat’ sharp peaks and ‘wiggles’. NO SMOOTHING is applied to the shown plots. power, efficiency, levels, balanced, impedance.Foobar 2000 for Dummies (Part 2) – Playing DSD – SACD plugin (0.9.x and 1.x.x Series).Foobar 2000 for Dummies (Part 1) – General Setup.Creative Sound BlasterX H7 (Tournament).
Subjectivist, Objectivist or Inbetweenivist ? (website links).
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