Alpine CDA-9887 - Manual

Experience music the way the artist intend-
ed. That’s idea behind IMPRINT—a hard-
ware/software combination that solves
acoustical problems presented to your
vehicle’s audio system. What’s more, it is
also said to improve the soundstage, tonal
balance and definition automatically. Just
plug it in and it does all the work in a matter
of minutes.
THE CHallEngE
When an artist lays down a track, they know
how they want it portrayed. When a recording
artist masters it, he does so with the same inten-
tions. But when we play it back in our vehicles,
are we hearing the music the way the artist
intended?
The sad reality to that question is usually not.
In fact, the automobile is one of the worst envi-
ronments to reproduce music. So how is one
to get around the problems? First we have to
understand what they are.
aCousTiCal ProblEm no. 1
An automobile’s cabin is filled with an abun-
dant amount of materials that reflect and absorb
sound, causing peaks and dips in music repro-
duction. For instance, windows reflect and ampli-
fy high frequencies. Leather-covered surfaces
like seats and hard plastic dashes and door
panels also reflect and change certain frequen-
cies. Carpeted areas in the cabin absorb and
suppress mid frequencies.
aCousTiCal ProblEm no. 2
The seating positions in an automobile are
skewed to one side of the vehicle or the other.
This means there are different pathlengths from
the loudspeakers to the listener, creating an
unbalanced listening experience. One way to fix
this issue is through time correction, but typi-
cally only one passenger gets to experience the
sound correctly and usually that’s the driver.
The combination of these acoustical problems
makes it difficult at best to see the clear picture
behind the composition. Instruments tend to
transpire from different areas of the vehicle, never
allowing for listeners to imagine the setting in
which they are presented.
WHaT is imPrinT?
The need for acoustical environment equaliza-
tion is very clear if we ever want to listen to music
as it was originally intended. This led Alpine to
come up with a unique way of determining the
artist’s directive. The basis is simple: What goes
in must come out. By measuring and under-
standing the gap in sound reproduction in the
vehicle Alpine was able to develop a corrective
tool to combat the acoustical problems in the
vehicle called IMPRINT.
The IMPRINT Sound System uses a hardware
plus software platform that not only overcomes
the acoustical challenges identified, but also
improves the soundstage, tonal balance and
definition of the music. Its design enables the
engineering and system tuning to be completed
in a fraction of the time of competitive systems.
At the heart of IMPRINT is MultEQ, which
was developed by the founders of Audyssey
Labs—Prof. Chris Kyriakakis and Prof. Tomlinson
Holman (inventor of THX theater sound)—in an
effort to understand and correct the fundamental
causes of room acoustical distortion. It works by
capturing frequency and time domain informa-
tion from the sound system within the acoustical
environment in order to identify the problems. It
then creates a set of equalization filters to cor-
rect for frequency response and time domain
problems for each speaker in the system. Based
on these measurements, MultEQ calculates an
equalization solution based on a selection of a
target curve from those developed by our team
of sound engineers. It’s a unique solution that
leads to spectacular sound quality experience
that’s customized to each specific vehicle and
sound system.
HoW DoEs iT Work
IMPRINT isn’t just another equalizer or time
correction device. It is the only system for the
automotive environment (to our knowledge) that
measures the entire listening area, capturing time
domain information from each listening location
and applies a proprietary method for combining
this information to represent all seat locations.
This results in a maximized listening experience
in all seats, not just for the driver.
During the measurement analysis, MultEQ
assigns more than 500 control points to the
plotted frequency response of the vehicle. Each
control point is then adjusted using MultEQ’s
dynamic filter methodology. These points opti-
mize the sound reproduction to the specific
vehicle’s listening environment with much greater
precision than can be achieved with traditional
parametric equalization.
How? First, MultiEQ creates a precise inverted
filter. The filter applies a peak of the same shape
everywhere there is a dip. Conversely, every peak
is corrected with a dip. With more than 500 points
used to create the model, the filter is incredibly
accurate—considerably more so than even the
best parametric or graphic equalizers, which are
typically limited to a certain number of bands.
Then there is the issue of time domain. This
is a fairly easy concept to understand. Sound
emits from a speaker eventually hitting your ears.
A few milliseconds later, copies of that same
sound signal hit your ears after being reflected
and modified by the car seats, dash, windows,
etc. Since these reflected sound copies arrive so
closely to the direct sound, your brain meshes
REVIEW
IMPRINT
ALPINE’S CDA-9887 TAKES ON HARSH ACOUSTICS
By CASEy THORSON
THE LEADING MONTHLY MOBILE A/V SOURCE
ELECTRONICALLY REPRINTED FROM APRIL 2008