Active Noise Control Stereo?

  1. I want to create an active noise stereo which works like the headphones except it's a big speaker. I need your help on how i would go about doing this? I ain't no electrical engineer or anything, in fact I have no knowledge whatsoever so try to help me using simple terms.
     
  2. jcsd
  3. berkeman

    Staff: Mentor

    Have you been through the intro page at wikipedia, and followed some of the links at the end of the article?

    http://en.wikipedia.org/wiki/Active_noise_cancellation

    .
     
  4. A question about active noise control. Does there need to be a specific angle at which the speakers must be at with the sound source?
     
  5. berkeman

    Staff: Mentor

    Yes, I believe that placement of both the noise source, the noise cancelling speaker(s) and the listener(s) are important. Can you tell us why that would be? BTW, do you know the speed of sound in air? And what is the normal range of frequencies of audio sounds that we hear? What are the corresponding wavelengths of sound in air? (Quiz questions for you)
     
  6. im a musician who is also studying physics at high school, and we have come to the part where we talk about how speakers work and so on, but what i asked and my teacher couldnt sanswer was, how does a speaker produce the different tone colours of instruments.
    if a violin plays a concert C and then a trumpet plays a concert C, how does the speaker change the tone of the sound so we recognise it as the respective instrument??
     
  7. vk6kro

    vk6kro 4,059
    Science Advisor

    A good quality speaker will just reproduce the waveform that comes from the instrument.

    Because the waveforms are different from each other, our ears recognise the instrument by its different waveform.

    This is the waveform of a saxaphone:
    http://hyperphysics.phy-astr.gsu.edu/HBASE/Music/saxw.html#c3
    [​IMG]

    This is the waveform of a clarinet
    http://hyperphysics.phy-astr.gsu.edu/hbase/Music/clarw.html
    [​IMG]

    Note that the speaker cone can only be in one position at a time, so it only traces one waveform, even if it is reproducing all the instruments of the orchestra.
     
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