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USING PASSIVE CROSSOVERS
A passive crossover is a circuit that uses capacitors and/or coils and is
placed on speaker leads between the amplifier and speaker. The
crossover delegates a specific range of frequencies to the speaker for
optimum driver performance. A crossover network can perform one of
three functions: High-Pass (capacitors), Low-Pass (inductors or coils)
and Bandpass (combination of capacitor and coil).
The most commonly used passive crossover networks are 6dB/octave
systems. These are easy to construct and require one component per
filter. Placing this filter in series with the circuit will reduce power to
the speaker by 6dB/octave above or below the crossover point
depending on whether it is a high-pass or low-pass filter. More
complex systems such as 12dB/octave or 18dB/octave can cause
impedance problems if not professionally designed.
Passive crossovers are directly dependent upon the speaker's imped-
ance and component value for accuracy. When passive crossover
components are used in multiple speaker systems, the crossover's
effect on the overall impedance should be taken into consideration
along with the speaker's impedance when determining amplifier
loads.
CAUTION: The Rockford Fosgate amplifiers are not recom-
mended for impedance loads below 2
Ω
stereo and 4
Ω
bridged
(mono) loads.
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