Marchand crossover questions

Discussion in 'Archived Threads 2001-2004' started by Abdul Jalib, Aug 15, 2002.

  1. Abdul Jalib

    Abdul Jalib Stunt Coordinator

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    The Marchand XM1 crossover is a "Fourth order constant voltage design (Linkwitz-Riley alignment)." The website claims:
     
  2. ThomasW

    ThomasW Cinematographer

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  3. Jon Hancock

    Jon Hancock Stunt Coordinator

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    The Marchand crossover generates a nominal 4th order L-R crossover by using a multiple pole state variable low pass filter. The output of the low pass filter is subtracted from the full range input to generate the high pass output. The low pass is formed by four integrator stages. The capacitor used in the integrator, in combination with the resistor feeding the integrator, sets the crossover frequency. This is a good way to implement the crossover, because even the minor errors from 1% resistors and 5% capacitors are compensated for so that the output will nominally sum to flat, without a small hole or peak in the transition region.

    Some of Marchand's crossovers use variable Q controlls to allow specifically altering the transition region Q, or level, while still maintaining accurate crossover frequency and slopes one into the stopband. IMO Marchand's products offer very good value for the money, and his success for many years was built on the strength of his crossovers.

    If you want to build a crossover with quality comparable to his double sided plated through hole boards, I doubt you'll be able to do it for as low a price as his kits cost. I have built several Marchand products (crossovers and passive preamps), and I do design and build some of my own units also (custom electronic crossovers with EQ, non loop feedback preamp circuits, for example,) but it's a much higher cost range than his kits. You can even buy his bare boards for the XM9 modules, for example, which is quite cost effective if you want to build your own modulees into existing equipment like power amps, or into your own chasis.

    Just read the material on his site thoroughly, and you'll get the picture.

    Best regards,

    Jon
     

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