W-Body Car Audio

Passive Crossover

If you are unfamiliar with crossovers, please read crossover basics.

Basics

A passive crossover works by manipulating the impedance of the drivers. For low-pass filters, the impedance of the circuit increases with frequency, while high pass filters increase the impedance as frequency decreases.  This is done with capacitors and inductors.

Advantages

The biggest advantage with passive crossovers is simplicity. If your head unit produces enough power, you can divide your signal between two or more speakers with a simple passive filter. 

Parts Express has a wide variety of crossover parts available. 

Disadvantages 

As you increase the slope of the crossover, you run into two problems:

1. The insertion loss goes up as you add components
2. With each order, there is an increased delay that is dependent on filter slope and frequency. I'll dive into that with a later article.