External low pass filter

Discussion in 'Archived Threads 2001-2004' started by Steve WC, Jul 14, 2002.

  1. Steve WC

    Steve WC Stunt Coordinator

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    Hi,
    Visiting from speaker sub forum were I started this thread regarding AH! noisekiller:
    http://www.hometheaterforum.com/htfo...threadid=82482
    It has been suggested I could build my own.
    If you can tell me how to go about it, and what I would need I would appreciate it.
    I would be most interested in mellowing out those frequencies responsible for sibilants.
    If you want to move this to e-mail please contact me at address provided by this forum.
    This is the link to the manufactured product:
    http://www.upscaleaudio.com
    Thank you for your help,
    Steve
    P.S. What does this mean:
    If you think you want one, just DIY. It is a zobel. Try a good 0.47µF cap with a 4.7R 2W resistor in series
     
  2. ThomasW

    ThomasW Cinematographer

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    The only way to know what the AH! device is doing is to pump a signal thorough it and measure any changes in the output frequencies. Until this is done it's impossible to duplicate it's function.
    You might want to start your research by reading the following article by Brian Cheney from VMPS http://www.vmpsaudio.com/nf.htm
     
  3. Chris Carswell

    Chris Carswell Supporting Actor

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    Here you go Steve. What he is talking about is a Zobel, or a
    impedance equalization circuits. They are used to counteract the rising impedance of a voice coil caused by inductive reactance. This problem mainly occurs in sub woofers, because of their large coils. A impedance equalization circuit, or Zobel, is usually placed after the crossover. It is simply a capacitor (C) and a resistor (Rc) in series, in parallel with the driver.
     

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