Infinity ALPHA 1200S, Руководство пользователя

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REFERENCE
®
THANKYOU for choosing an Infinity
®
Reference
®
Series 1000s or 1200s
subwoofer. These Reference 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 1000s or 1200s subwoofer.
Although this manual does provide general
instructions about installing these
Reference 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 Infinity 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.
BOX CONTENTS
(1) 1000s or 1200s subwoofer
(1) Owner’s manual
(1) Technical data sheet
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
Infinity speakers when combined with
high-power amplification may exceed
safe levels for extended listening. Using
low volume levels is recommended when
driving. Infinity Systems accepts no
liability for hearing loss, bodily injury, or
property damage as a result of use or
misuse of this product.
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.
See accompanying data sheet for specific
enclosure dimension requirements.
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 1000s or 1200s 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.
T
HE
I
NFINITY
R
ECOMMENDATION
1000s and 1200s subwoofers in sealed
enclosures are recommended for
enthusiasts who prefer accurate music
reproduc-tion 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 on the technical data sheet
accompanying this manual represents the
best compromise between low-frequency
extension and flat response.
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. The enclosed technical data
sheet includes frequency response graphs
that show both the subwoofer’s “in-car”
response (which factors in this vehicle
transfer function) and its “out-of-car”
response (which does not).
SUBWOOFER
ENCLOSURE TYPES
Reference 1000s and 1200s 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-han-
dling 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.
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
EN