Loudspeaker Crossover 6 dB Calculation

This page calculates the coil and the capacitor for a 1st order crossover for a 2-way loudspeaker. The crossover only has a coil for the bass speaker and a capacitor for the tweeter to separate the frequency. The attenuation is 6dB per octave.

Properties of the crossover of the 1st order

The simplest crossover is the 1st order crossover with only one coil for the bass speaker and a condenser for the high-frequency range. A 1st order crossover has good phase and transient response. However, the attenuation is only 6dB per octave. As a result, a relatively large number of high frequencies are fed to the bass speaker and the tweeter also receives frequencies far below the crossover frequency.

In order to get a clean reproduction, the transmission characteristics should be approx. 2 octaves within the overlapping area be linear. In addition, it must be taken into account that the tweeter is more heavily loaded by the lower frequencies.

Also pay attention to the polarity of the loudspeakers. Since the current in the coil lags behind the voltage by 90°, and at the capacitor the voltage also lags behind the current by 90°, the membranes of the loudspeakers move opposite. To eliminate this effect, one of the loudspeakers must be connected with reversed polarity.

Formulas