Harman-Kardon 120.3SE Speaker System User Manual

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Playing loud music in an automobile can perma-
nently damage your hearing, as well as hinder
your ability to hear traffic. The maximum volume
levels achievable with Infinity speakers, combined
with high power amplification, may exceed safe
levels for extended listening.
We recommend using low volume levels when
driving. Infinity accepts no liability for hearing
loss, bodily injury, or property damage as a result
of use or misuse of this product.
Depending on the size of the vehicle’s interior
listening space, reproduced bass frequencies
below 80Hz are boosted by nearly 12dB per
octave as frequency decreases in the car.
This effect, known as the vehicle’s transfer
function, plays an important part in shaping over-
all in-car response and is displayed graphically,
along with freespace response, on the enclosed
data sheet for your Kappa subwoofer.
Kappa Series subwoofers are optimized to
perform best in small sealed, vented, and
prefabricated bandpass enclosures. While
infinite-baffle mounting is possible, power
handling will be greatly compromised because
there is no enclosed volume of air to prevent the
speaker’s cone from moving past its limit. For this
reason, we do not recommend infinite-baffle
mounting for Kappa Series subwoofers.
You should choose an enclosure based on the
following factors: the type of music you listen to,
the amount of amplifier power required to drive
the subwoofer, and the volume of interior space
needed for the subwoofer enclosure.
Because a sealed enclosure provides the most
control over the subwoofer’s movement, an
enclosed subwoofer will handle more power than
one mounted in another type of enclosure. Also,
sealed enclosures provide more accurate sonic
reproduction than other enclosure types, so they
are well suited to all types of music.
Sealed-enclosure construction is straightforward,
and there are many prefabricated boxes available.
Optimum sealed enclosures are always smaller
than other types of optimized enclosures for a
particular speaker, so they will only require the
smallest amount of space inside the vehicle.
Vented enclosures provide better efficiency in
the 40Hz to 50Hz range, but at the expense of
reduced sound output in the lowest octave
(below 40Hz) and some loss of control and
power handling. When using a small amplifier,
a vented box will provide more bass output from
less power than a sealed enclosure will.
Vented enclosures are also well suited to a variety
of music types. However, because the required
enclosure volume and port size have a specific
relationship with the characteristics of the sub-
woofer, each enclosure must be built exactly to
the provided specifications. While there are some
prefabricated vented boxes available, matching
one to a particular subwoofer is difficult.
Moreover, an optimum vented enclosure is
always larger than the optimum sealed box for
the same subwoofer and will require more space
inside the vehicle.
If you wish to use a vented enclosure, we strongly
recommend having your authorized Infinity dealer
build it or that you verify that your design is
correct before you start building it yourself.
Bandpass enclosures often provide the most out-
put available from any amplifier and subwoofer
combination at the expense of sonic accuracy.
If sheer SPL (sound-pressure level) is what you
desire most, then choose a bandpass enclosure.
However, bandpass-enclosure design is very tricky
and may require the aid of a computer and enclo-
sure design software. If you are an experienced
installer or have some woodworking experience,
you may wish to build the enclosure described in
the design sheet included with this subwoofer.
Fortunately, there are many prefabricated band-
pass boxes available and they are all optimized to
extract the most output possible from any sub-
woofer. Bandpass enclosures can be quite large
and may require a lot of space inside your
Thank you for choosing an Infinity Kappa Series subwoofer. Kappa Series subwoofers
are designed to suit a broad range of mobile 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 ensure
maximum subwoofer performance, we strongly recommend that installation be left to a qualified pro-
fessional. Although these instructions explain how to install a Kappa Series subwoofer in a general
sense, they do not show box-construction details and exact installation methods for your particular
vehicle. If you do not feel you have the necessary experience, do not attempt the installation yourself,
but instead ask your authorized Infinity dealer about professional installation options. Remember to
keep your sales receipt with this manual in a safe place so both are available for future reference.
Type: 10" subwoofer,
single-voice coil
Nominal Impedance: 4 ohms
Power Handling: 275W RMS, 1,100W Peak
Sensitivity (2.83V, 1m): 90dB
Frequency Response: 20Hz – 250Hz
Mounting Depth: 6-1⁄16" (154mm)
Cut-out Diameter: 9-1⁄ 8" (232mm)
Type: 12" subwoofer,
single-voice coil
Nominal Impedance: 4 ohms
Power Handling: 300W RMS, 1,200W Peak
Sensitivity (2.83V, 1m): 92dB
Frequency Response: 18Hz – 250Hz
Mounting Depth: 6-5/16" (161mm)
Cut-out Diameter: 10-15⁄16" (278mm)