The most commonly used filter networks are 6 dB per
octave systems. These are easy to construct and require
a minimum number of parts. A filter network can perform
one of three functions. These are highpass (capacitors),
lowpass (inductors, chokes or coils) and bandpass (com-
bination of a capacitor and a coil).
The result, limiting the types of frequency to the speaker,
is directly dependent upon the speaker’s impedance and
component values.
The most common filters used in speaker crossovers, as
stated above, are 6 dB per octave which use one compo-
nent per filter. Placing this filter in series with the circuit will
reduce power to the speaker by 6 dB per octave above or
below the crossover point depending on whether it is a
High Pass or Low Pass filter. When passive crossover
components are used in multiple speaker systems, the
crossover system's effect on the overall impedance should
be taken into consideration along with the speaker's
impedance when determining amplifier loads.
More complex systems such as 12 dB or 18 dB per octave
can cause impedance problems if not professionally de-
signed. If such a system is required, we recommend
consulting an Authorized Rockford Fosgate Dealer.
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