Loudspeaker System Crossover Network

Building a crossover for your speaker system is easy. Here the simple passive schematic diagram of audio crossover:

Loudspeaker System Crossover Network circuit diagram

Loudspeaker System Crossover Network Notes:

  • Capacitor must be non-polar capacitor types with a voltage rating of 50 volt or more (preferably 100 volt).
  • Capacitor may be paralled to achieve specified values.
  • Inductors should be air core. Do not mount inductors in top of each other.
  • Resistors should be 100 Watts or more.

Passive crossover is made entirely of passive components, arranged most commonly in a Cauer topology to achieve a Butterworth filter. Passive filters use resistors combined with reactive components such as capacitors and inductors. Very high performance passive crossovers are likely to be more expensive than active crossovers since individual components capable of good performance at the high currents and voltages at which speaker systems are driven are hard to make. Polypropylene, metalized polyester foil, paper and electrolytic capacitors are common. Inductors may have air cores, powdered metal cores, ferrite cores, or laminated silicon steel cores, and most are wound with enamelled copper wire. Some passive networks include devices such as fuses, PTC devices, bulbs or circuit breakers to protect the loudspeaker drivers from accidental overpowering. Modern passive crossovers increasingly incorporate equalization networks (e.g., Zobel networks) that compensate for the changes in impedance with frequency inherent in virtually all loudspeakers. The issue is complex, as part of the change in impedance is due to acoustic loading changes across a driver’s passband.

7 comments

  1. pls i need a schematics for building a crossover for a loudspeaker with the mid-range speaker of 200watts and the tweeter of also 200watts

  2. Nope! you should parallel the line side and connect the secondary in SERIES! that way you get a 24 volts center-tapped x’former. but be careful to use x’former with the same rating. If you connect the secondary in parallel, you also get 12 volts output.

  3. You parallel the primary (line) side, and SERIAL the secondary (12 volt) sides to get 24 volts. AC adds just like DC in this case. As a bonus, when you do this, you actually get at center tap on the 24 volt results. The serial connection works just like a center tap, if you need it.

    BTW, the “capacitor voltage doubler” is for low current applications and only need one transformer. The capacitors are charged by the rectifiers, and add up like battery cells in series. But they can’t discharge much at all or they won’t be like batteries any more. So stricty low current if you need nice DC out. (Preamp, not power amp…)

  4. Yes you can combine two 12 volt transformer.Just parallel the primary side and the same with the secondary side.

  5. please am an electrical student and want some help. please how can i connect two transformers of the same or different voltage to one circuit board like power amplifiers. I mean i have two 12volts transformers but i don’t know how to connect or combine to get 24volts and my power amplify needs 24volts power supply. A friend to told me u can held that’s why am in your mission. please help me.THANKS

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