JBL S3-1224 Benutzeranleitung

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SERIES III SUBWOOFERS
THANK YOU for choosing a JBL 
Series III subwoofer. These subwoofers 
are designed to suit a broad range of car 
audio applications and can be used in a 
wide variety of enclosure types to produce 
extended, powerful bass in a limited 
amount of vehicle space. To get the most 
performance from your new subwoofer, it 
is strongly recommended that you have a 
qualified professional install your 
subwoofer. Although this manual does 
provide general instructions about 
installing these Series subwoofers, it does 
not include enclosure construction details 
or exact installation methods for any 
particular vehicle. If you do not feel that 
you have the necessary experience, do not 
attempt the installation yourself, but 
instead ask your authorized JBL dealer 
about professional installation options.
Remember to keep your sales receipt in a 
safe place, along with this manual, so 
that both are available for future 
reference.
WARNING
Playing loud music in a vehicle can hinder 
your ability to hear traffic and 
permanently damage your hearing. The 
maximum volume levels achievable by JBL 
speakers when combined with high-power 
amplification may exceed safe levels for 
extended listening. Using low volume 
levels is recommended when driving. JBL, 
Inc. accepts no liability for hearing loss, 
bodily injury, or property damage as a 
result of use or misuse of this product.
REPRODUCING 
BASS IN VEHICLES
Depending on the size of your vehicle’s 
interior listening space, reproduced bass 
frequencies below 80Hz will be boosted 
by nearly 12dB per octave as frequency 
decreases. This phenomenon, known as 
the vehicle’s transfer function (or cabin 
gain), plays an important role in shaping 
the subwoofer’s frequency response in 
your vehicle.
SUBWOOFER
ENCLOSURE TYPES
The subwoofers are designed to perform 
best in moderately sized sealed 
enclosures, vented enclosures and 
prefabricated band-pass enclosures. 
Infinite-baffle mounting is possible, but 
the subwoofer’s mechanical power 
handling will be reduced because there 
will be no volume of air to stiffen the 
subwoofer’s suspension and prevent 
overexcursion. If you choose infinite-
baffle mounting, consider the RMS and 
peak power-handling ratings to be half of 
what is listed in the specifications in this 
manual.
You should choose an enclosure type 
based on the amount of cargo space you 
can devote to the enclosure, the amount 
of power you will use to drive your 
subwoofer(s), and your listening habits.
handling at and above resonance, but 
reduced mechanical power handling below 
resonance. Since the subwoofer cone and 
voice coil don’t move much at resonance, 
airflow across the voice coil is minimized 
and thermal power handling is reduced 
slightly at resonance.
Vented enclosures provide better 
efficiency in the 40Hz – 60Hz range, at 
the expense of sound output in the lowest 
octave (below 40Hz). The use of an 
infrasonic filter is recommended with 
vented enclosures. An optimum vented 
enclosure for a Series subwoofer is larger 
than an optimum sealed enclosure.
V
ENTED-
E
NCLOSURE 
P
ERFORMANCE 
A
DVANTAGES
• An optimum vented enclosure has 
greater efficiency and higher output in 
the 40Hz – 60Hz range than an optimum 
sealed enclosure.
• An optimum vented enclosure provides a 
greater sensation of bass than an 
optimum sealed enclosure.
• A subwoofer in an optimum vented 
enclosure will require less amplifier 
power to achieve a given acoustic 
output (down to the enclosure’s 
resonance frequency) than in an 
optimum sealed enclosure.
V
ENTED-
E
NCLOSURE PERFORMANCE 
TRADE-OFFS
• Reduced output in the lowest octave 
(below 40Hz).
• Reduced mechanical power handling 
below the enclosure’s resonance 
frequency. The use of an electronic 
infrasonic filter is strongly recommend-
ed to reduce the chance of overdriving 
the subwoofer below the enclosure’s 
resonance frequency.
• An optimum vented enclosure will 
always be larger than an optimum 
sealed enclosure.
V
ENTED-
E
NCLOSURE 
C
ONSTRUCTION
Vented-enclosure construction is more 
difficult than the construction of a sealed
enclosure. The enclosure volume and port
dimensions have a specific relationship 
with the physical and electromechanical
characteristics of the subwoofer, 
requiring that the recommended 
enclosure volume and port characteris-
tics be strictly observed. As with sealed 
enclosures, use medium-density 
fiberboard (MDF), glue and screws to 
construct the enclosure, and seal all 
joints with silicone caulk.
R
ECOMMENDATION
Subwoofers in vented enclosures are 
recommended for enthusiasts who prefer 
accentuated bass response, for those who 
have plenty of cargo space to devote to a 
subwoofer enclosure and for those who 
will use a less powerful amplifier to drive 
their subwoofer. The volume and port 
dimensions indicated must be followed 
precisely to ensure optimum 
performance.
MOUNTING THE
SUBWOOFER
The subwoofers should be
mounted from the outside of the 
enclosure.  Use the included foam 
mounting gasket to ensure a leak-free 
seal between the subwoofer frame and 
the enclosure.
CONNECTING THE
SUBWOOFER
S
ETTING THE 
I
MPEDANCE
The Series III subwoofers both feature 
the Selectable Smart Impedance
(SSI) switch. This exclusive feature lets 
you set the subwoofer’s impedance to 
either 2 ohms or 4 ohms with the flip of a 
switch (see illustrations below). This 
allows you to extract the most from your 
subwoofer amplifier in any situation.
The SSI 2-ohm setting increases the 
subwoofer’s output over the 4-ohm 
setting by up to 3dB, depending on the 
amplifier. Performance is identical in all 
other respects. If the connected amplifier 
is rated for 2-ohm operation and its 2-ohm 
power ratings are within the subwoofer’s 
power-handling specifications, setting 
the SSI switch in the 2-ohm position will 
achieve maximum output.
S
EALED 
E
NCLOSURES
The air trapped inside a sealed enclosure 
is compressed when the subwoofer moves 
rearward and is rarefied when the 
subwoofer moves forward. In both cases, 
the air inside and outside the box will 
seek equilibrium by pushing and pulling on 
the subwoofer cone. The result is a 
stiffer suspension when compared to the 
subwoofer operating in free air. This 
means that the subwoofer’s cone will be 
harder to move at low frequencies, a 
condition which protects the subwoofer 
from  physical overexcursion, but 
requires more power than other designs 
to achieve a given acoustic output.
S
EALED-
E
NCLOSURE 
P
ERFORMANCE 
A
DVANTAGES
• The in-vehicle performance will have 
  the flattest overall frequency response.
• The in-vehicle response will have the
  widest bandwidth. (Usable low-frequency
  response inside the vehicle will be 
 below 20Hz.)
• An optimum sealed enclosure will always
  be smaller than an optimum enclosure of
 another type.
S
EALED-
E
NCLOSURE 
P
ERFORMANCE 
T
RADE-OFFS
• An optimum sealed enclosure will have
  lower overall efficiency than an 
  optimum enclosure of another type.
• A subwoofer in an optimum sealed 
  enclosure will require more amplifier 
  power to achieve a given acoustic 
  output than in an optimum enclosure of 
 another type.
S
EALED-
E
NCLOSURE 
C
ONSTRUCTION
Sealed-enclosure construction is straight-
forward and forgiving of errors in volume 
calculation, but air leaks should be 
avoided. Use medium-density fiberboard 
(MDF), glue and screws to construct the 
enclosure, and seal all joints with silicone 
caulk.
R
ECOMMENDATION
Subwoofers in sealed enclosures are 
recommended for enthusiasts who prefer 
accurate music reproduction and flat 
frequency response, for those who have a 
smaller space to devote to a subwoofer 
enclosure, and for those who have plenty 
of amplifier power devoted to driving the 
subwoofer. The sealed-enclosure design 
indicated in this manual represents the 
best compromise between low-frequency 
extension and flat response.
V
ENTED 
E
NCLOSURES
A vented enclosure acts like a sealed 
enclosure at frequencies above its tuned 
(resonance) frequency. At resonance 
(which is defined by the vent), the vent 
produces the majority of sound – the 
subwoofer cone is nearly stationary while 
the air inside the vent vibrates. This 
provides greater mechanical power 
2-Ohm Setting
4-Ohm Setting