Passive crossover gurus!

Discussion in 'Home Theater Projects' started by Deyton, Jun 26, 2003.

  1. Deyton

    Deyton Auditioning

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    Anybody here build their own passive crossovers? I was in the process of modifying these stock crossovers (or probably just building new ones) to allow for biamping when i realized that i don't understand circuit boards!

    Can somebody look at this pic and tell me what's going on? (The parts connected by blue lines are the same). It would be extrememly helpful if someone could translate this into one of those standard crossover diagrams.

    I'm not sure about the inductor values, the little one might be .18mH, the caps are 12uF and 5.6uF. The crossover point is supposed to be ~3500Hz. Playing around with a linkwitz crossover calculator, it seems like the woofer is only 2 ohms! (speaker is 4 ohms nominal, it's a car speaker)I'm thinking this may hinder my biamping ambitions.

    Pic
     
  2. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    It's a simple Linkwitz Riley 2nd order crossover. The tweeter has reversed polarity. If you look at any Linkwitz Riley 2nd order crossover you'll see the correct wiring diagragm.

    You are right about the inductor quantities. My estimation is that they are .36mH for the HP and .18mH for the LP. You should probably match the gauge of the wire so you get the same DCR.

    Bi-amping will be simple but remember that the impedance of the woofer is 2 ohms so keep that in mind.

    If you are confused how to design a crossover for bi-amping let me know and I can email you a circuit diagram. I think that once you see the diagram for a 2nd order L-R crossover it should be self explanitory.
     
  3. Deyton

    Deyton Auditioning

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    Actually, the impedance of the woofer is not 2 ohms, because the dcr is 3.5. Apparently they're crossed over at different frequencies. Anyways, i got it figured out now. thanks for your help.
     
  4. Deyton

    Deyton Auditioning

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    Well I thought that I figured it out, but then I decided not to go on with the building.

    Now I've started thinking about it again, but only by modifying my current crossovers. I drew a diagram of what i will do, can someone tell me if it is correct?

    Pic sorry it's so messy [​IMG]
     

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