CrossOver is a powerful plug-in designed to divide an incoming audio signal into up to four distinct frequency bands. This functionality enables the creation of custom multiband effects within modular or subhost environments, offering precise control over how different frequency ranges are processed. When configured with just two bands, CrossOver allows for specialized bass effects by keeping the low frequencies untouched while applying effects exclusively to the higher frequency range.

The signal splitting is achieved using complementary pairs of Linkwitz-Riley lowpass and highpass filters, which provide a smooth and clean crossover between frequency bands. Users can adjust the filter slopes between 12 and 96 dB per octave, tailoring the sharpness of the frequency separation to their needs. This flexibility ensures that the transitions between bands are musically transparent and well-suited for a variety of audio applications.

For setups involving more than two frequency bands, CrossOver employs a hierarchical approach to signal splitting. The input is initially divided into two bands—low and high—and each of these can be further split to create additional bands. This method maintains optimal phase alignment and sound quality while providing detailed control over multiple frequency ranges, making CrossOver an essential tool for crafting precise multiband audio effects.