Crossover Modeling Program

Discussion in 'Home Theater Projects' started by PasqualeF, Apr 26, 2003.

  1. PasqualeF

    PasqualeF Auditioning

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    I have a crossover modeling program called - wait for it - Crossover Modeling Program. It was included with a loudspeaker book I bought. Is anybody familiar with this software and use it regularly? If not then let me explain the problem.

    It is a crossover design program that plots freq response taking into account:
    1. The actual freq response of the driver (you must have a on-axis response data file for each driver)
    2. The impedance curve of the driver (again must have a file for this)
    3. How the crossover will affect the output based on the varying impedance of the driver[/list=1]
      To cut a long story short a response curve is plotted showing how the system will perform with different crossover designs.

      Now this is the problem. You can put a cap or a resistor anywhere by it self. A coil however can only be placed in the network with a resistor in series before it. You can not put in a value of zero for the resistor, it must have a value. Does anyone know why you can not put a stand alone coil?

      Here's the weird part. The book has projects which include crossover schematics. Nearly all of which have coils with no resistors before them just as you would in a normal network. The program has project files of all the projects in the book. When you load a project, look at the crossover schematics and guess what, all the inductors have a resistor before them! The coils are all the same values as the designs in the book. Just that there is always a resistor thrown in. Usually about a 2-3 ohm.

      Man does anybody even understand what I'm talking about?!? This must be confusing. Am I missing something really simple here? I hope someone out there has the same program.
      Thanks
      Pat
     
  2. Patrick Sun

    Patrick Sun Moderator
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    Inductors have a small resistance value associated with them, so that's why the program is requiring.

    The resistance is mainly due to the gauge of the wire in the inductor. The lower the gauge, the lower the resistance value for the inductor. This is the reason why some DIY speaker makers will use inductors with 14/16 gauge wire to reduce the resistance losses in the midwoofer's crossover network which robs driver output/sensitivity levels. But most mass market speaker makers will use the inductors made of thin wire (18/20/24 gauge) to cut down on cost/weight of the inductors.

    If you have a multimeter, you can measure the DC resistance of inductors, that's the resistance of the inductor that is introduced into the crossover network.
     
  3. PasqualeF

    PasqualeF Auditioning

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    Ok that makes a lot of sense. So the program asks for the DC resistance because that would also effect the way the network effects the output.
     

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