The frequency point where a system hands off duties between two speakers or drivers — for example, from a subwoofer to your main speakers.
A crossover frequency (often written fc) defines where one driver's output rolls off as another driver's takes over. Set it too high and you'll hear a driver straining outside its comfortable range; set it too low and you may get a gap or overlap in coverage.
Crossover points are usually chosen with both drivers' Fs, Xmax, and off-axis response in mind — not just a round number. A subwoofer crossover that's right for one room or vehicle cabin may need adjustment in another, since room and cabin acoustics shift how frequencies blend at the listening position.
| Context | Typical Home Audio | Typical Car Audio |
|---|---|---|
| Sub-to-main crossover | 60 – 100 Hz | 70 – 90 Hz |
| Tweeter-to-mid crossover | 2,000 – 3,500 Hz | 2,500 – 4,000 Hz |
