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English
Crossover Network Introduction
It is common knowledge that the automotive interior is one of the most inhospitable
environments for high-fidelity sound, and that every vehicle poses its own unique set of
installation and acoustic challenges. While many of these problems can often be over-
come with proper speaker placement, equalization, or other techniques, the attempt is
a time consuming task without guaranteed results. Yet with all these tools and methods
available, it is surprising to realize that one of the most powerful tuning tools has been
misunderstood or neglected by so many for so long. It is for this reason that Alpine has
developed the most advanced crossover network design in the history of car audio.
Much of the difference between demo-board and in-car performance can be attributed
to the fact that crossover networks have been traditionally tuned for only one specific
application – usually the demo-board. Without taking into account typical real world
installations, the transition between drivers and resultant frequency response will be
degraded for the majority of vehicles that installers are confronted with today. Through
Alpine’s unique phase coherent flat summation design methodology, however, it is now
possible to optimize performance for a variety of installations by intentionally altering
various filter characteristics. By achieving an “in-phase” condition between drivers in
the overlapping frequency range at the listening position, image smear, response aber-
rations and other typical problems can be dramatically reduced or eliminated altogether.
This “phase linkage” technique can be thought of as a kind of passive time correction in
the crossover region.
With Alpine’s introduction of such revolutionary processing technologies as digital time
correction and adaptive equalization, all of this may seem superlative. Unfortunately
however, such processing can significantly increase system complexity and therefore
may not be practical for every situation. Additionally, without careful use of time correc-
tion for each individual speaker in the system, integration problems between them can
remain. Subsequently, it may be advantageous to use such processing to compensate
for seating position bias in conjunction with the phase correction of the passive network
for the transition between individual drivers. Simply stated, the flexibility of the
AlpineF#1Status™ crossover network allows it to be a complimentary solution for achiev-
ing the best of both worlds, either as a stand alone solution or an integral component of
a partially active system.
As with all AlpineF#1Status™ products, it is the attention to the smallest details that
truly brings out ultimate performance... or in a word, MicroDynamics™. From the hand
coated crosscut wood fiber cones to the symmetric drive motor structures, nothing is
left to chance. This philosophy is carried throughout every aspect of the SPX-Z18T
speaker system, including the components, layout and design of the crossover network.
All series capacitors are the highest grade metalized polypropylene, and all series
inductors are heavy gauge air core. Even parallel inductors are of powder core con-
struction, to maximize consistancy and sound quality. All elements are intentionally placed
in such a way to as to minimize any chance for magnetic or thermal influence, and all
signal path lengths are minimized with extra heavy circuit board traces. In the end, this
level of quality and attention to detail has but one purpose, to bring true sonic realism to
the automotive environment once and for all.