Alpine 3681 Manual De Instalación Y Operación página 10

CROSSOVER NETWORKS:
Acrossover network divides the audio spectrum in-
to different segments. This segmentation is based
on the frequency of the signal. The crossover net-
work actually employs filters that pass a certain
range of frequencies and block the rest. This way,
the signal can be separated into a set of signals with
different frequency response ranges.
/®
Audio Signal High Freq.
/®\ To Midrange
Drivers
@ X @ X® Midrange
Crossover Network O\
Low Freq.
To Tweeters
To Subwoofers
The Lower Cutoff (or High-Pass Crossover point) of
the network is the lowest frequency at which the le-
vel is no more than 3 dB below the reference level
established in the pass-band.
The Upper Cutoff (or Low-Pass Crossover point) of
the network is the highest frequency at which the
level is more than 3 dB below the reference level es-
tablished in the pass-band.
Upper
Cutoff
Increasing Frequency
A crossover network section does not necessarily
have both the lower and higher crossover frequen-
cies:
1, LOW-PASS CROSSOVERS: Filters with only an
upper cutoff frequency. Subwoofer outputs are
generally low-pass.
2. HIGH-PASS CROSSOVERS: Have a lower cut-
off frequency only. Tweeter (High) outputs are gen-
erally high-pass.
3. BANDPASS CROSSOVERS: Have both lower
and upper crossover points. These filters are made
by adding a Low-pass and a High-pass crossover
together in series. Midrange crossovers are gener-
ally bandpass.
\ Low-Pass
+
/ High-Pass
Bandpass
Increasing Frequency
There are two methods of implementing a cros-
sover network:
PASSIVE NETWORKS:
Consist of inductors, capacitors, resistors or a com-
bination of these components. The term "passive"
refers to the fact that there are no active compo-
nents (such as transistors or op-amps) in these sys-
tems. Passive networks are inserted between the
amplifier and the speakers. They act on the amplifi-
ed speaker-level outputs of the amp. Passive ne-
tworks are used in most automotive 2 or 3 way
speakers and home speaker systems.
SIGNAL
PROCESSOR
Pre-Amp
Level Output
POWER AMP
Speaker
Level Output
PASSIVE
DIVIDING
NETWORK
Speaker
Level Outputs
SPEAKERS