Sine Wave Versus Square Wave

Discussion in 'Speakers' started by Darren{Moo}, Feb 24, 2004.

  1. Darren{Moo}

    Darren{Moo} Extra

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    Could anybody tell me the difference calibrating using a sine wave vs. a square wave. Is one preferable over the other, do they serve completely different purposes, etc...
     
  2. GrahamT

    GrahamT Supporting Actor

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    A sine wave is an analog signal and a square wave is a digital signal. Speakers cannot reproduce a square wave signal.
     
  3. Chu Gai

    Chu Gai Lead Actor

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    Although square waves have their place in testing various aspects of circut design, there is nothing to commend their use for calibration purposes such as in balancing your system. Mathematicaly, a square wave can be represented as a summation of sine waves but to do so accurately requires that the series be carried out to infinity. Given that your electronics are bandwidth limited and that even if they weren't then your speakers are in all probability unable to reproduce a square wave with any semblance to the original wave form then what's the point? What is it you are looking to do?
     
  4. PaulT

    PaulT Supporting Actor

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    Not necessarily true. A wave representing 2 conditions (on/off) can be represented by a square wave, but it does not have to be digital. An overdriven analog signal will form a square wave (a heavily driven sine wave will clip the top and bottom of the wave and appear square).

    Speakers can try and reproduce a square wave as they will try and reproduce a DC input (for example if you hook up a 9V battery across the terminals), but they will not particularly like it for any length of time.

    Darren, you may be confusing sine/square with a sine wave (or fixed frequency signal) and pink noise (a signal with equal energies in all octave bands).

    Your receiver test tones are pink noise used to set speaker levels. To plot frequency response you would typically use single frequencies.
     
  5. Darren{Moo}

    Darren{Moo} Extra

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    Thanks for the information. I was perusing the manual for a tone generator and it referenced output in either a sine wave or square wave. It seems that all the test tones I was familiar with were sine wave tones, so I was curious about the other. Thanks.
     
  6. Stephen Weller

    Stephen Weller Stunt Coordinator

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    ($0.02 warning)

    If you scope a clipped sine wave, it may look like a square wave until you zoom in on it. Then you'll start to see the rates of rise and fall. But a true square wave will remain...uh...square.
     

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