Using The Crossovers - Rockford Fosgate Power 360 Installation Manual

USING THE CROSSOVERS

The crossovers are usually used in biamplified mode. They
separate the frequencies in the input signal into low and high
frequencies
amplifiers. (See the Amplifier Block Diagram for a system
layout.) When the crossovers are used for biamplified systems,
the High and Low frequencies are usually set equal.
The most common
is 250 Hertz. This frequency setting keeps the worst of the low-
frequency power out of the midranges but doesn't require the
woofers to do a great deal of midrange. For systems whose
midrange speakers cannot handle a lot of power, a 600 Hertz
crossover setting will save the drivers. For systems with
essentially full-range
midranges, a 100 Hertz crossover frequency gives better
imaging by putting more midrange energy up front with the
tweeters.
The main use of the 4000 and 15000 Hertz crossover frequencies
is for complex systems which use the amplifier as a midrange-
tweeter biamplified
crossover point
Hertz might be used with an extremely rugged tweeter or a small
midrange.
The crossover system can be used to do a certain amount of
equalization for correcting response problems in the car. If the
crossover frequencies in a biamplified system are "under-
lapped"; that is, the low-frequency crossover is set one notch
lower than the high-frequency crossover, a 6dB dip appears in
the overall
centered between the low and high crossover settings. If the
crossovers are
peak of about 2 dB, again centered between thecrossover
settings. The "dip" response in particular can improve cars
which have a bad midrange bulge at around 150-200 Hertz, as
often happens. Setting the low crossover at 100 Hertz and the
high crossover at 250 Hertz produces a 6 dB dip at 160 Hertz,
removing tubbiness and unnatural male voices produced by the
car's resonance. See "Crossover Response Curves" for a graph.
for the separate
crossover
front
system.
for most
"summed" system
"overlapped", the response shows a gradual
woofer
frequency
speakers or
4000 Hertz is a satisfactory
midrange-tweeter
response.
and high
for biamplified
very rugged
combinations.
Its frequency
frequency
systems
and large
1500
is