6 Loudspeaker cabinets

6.6 Crossovers

Few single speakers can reproduce the entire audible range. The ones that can are likely to be fit into high-end audiophile systems. Normal people resort to using different drivers optimized for a certain frequency range, and fit them into the same cabinet. Two-way systems are the most common, as they are relatively easy to design and give good results at low cost.

Using optimized drivers means having to split up the frequency range into bands (much like equalizer bands 2.7.3 Frequency). The separation range is called the crossover frequency. One driver's output rolls off, while the next one gradually takes over. The rate at which this takeover is done is called slope. Slopes are usually 6, 12, 18 or 24 dB per octave.

Crossing over can be done in two ways. Passive crossovers go in between the power amplifier and the loudspeaker. Usually the crossover is built into the speaker cabinet. This is by far the most common way for low to medium power. For high power and high fidility systems, active crossovers 5.12 Bi-amping are used. They are connected before the power amplifier stage, requiring each driver or driver group to have their own amplifier. This yields more control and higher sound quality.

© Joris van den Heuvel 2001-2009