Rockford Fosgate S1-408 - Manual (Page 5)

2
Suspension – The suspension of a speaker is the part of the speaker
which controls the motion of the cone. This is what changes the
electrical energy to sound energy. The surround is constructed from
a dual laminated foam which ensures linear motion of the cone while
resisting mechanical and environmental damage.
Dual Input Terminals – To facilitate hook-up in multiple driver
configurations, each positive and negative terminal has two connect-
ing lugs. The positive terminal is identified by a dot which also
indicates the speaker's impedance. A red dot is used on a 8
Ω
speaker,
a violet dot on a 4
Ω
speaker.
L
OW
F
REQUENCY
S
PEAKER
S
YSTEMS
The Series 1 Woofers require an enclosure to achieve optimum
results. The enclosure allows the speaker to operate at lower frequen-
cies with improved power handling. The two most commonly used
types of low frequency speaker systems are acoustic suspension and
bass reflex. The acoustic suspension enclosure, commonly referred to
as a sealed box, relies upon the changing air pressure in a tightly
sealed chamber of its operation. The bass reflex, commonly referred
to as a ported enclosure, uses a vent inserted into the box which takes
over for the speaker at a desired frequency which is determined by the
internal volume of the enclosure and the size of the vent used. The
Series 1 Woofer will yield optimum performance in a ported enclo-
sure.
U
SING
T
HE
S
ERIES
1 W
OOFERS
Speakers are built in different sizes to optimize their performance in
different frequency bands. Crossovers are used to route the different
frequency bands for each appropriate speaker. There are two opera-
tional types of crossover: active and passive. An active crossover is an
electronic filter which is placed before the amplifier and separates the
signal fed to different amplifiers in the system. A passive crossover is
positioned after the amplifier and separates the signal fed to each
speaker in the system. Active crossovers offer the accuracy and
flexibility needed for a sophisticated system and are used in complex
multiple amp designs. Passive crossovers (capacitors and inductors)
allow the use of multiple speakers in a simple system which can easily
be expanded over time. We recommend using a 6dB per octave,
100Hz low-pass crossover for the Series 1 Woofers when used with
a passive system.
To customize the installation, try adjusting the crossover point one
octave up or down to optimize the system staging.