Alpine CDA-9887 User Manual

THE LEADING MONTHLY MOBILE A/V SOURCE

ELECTRONICALLY REPRINTED FROM APRIL 2008

IMPRINT

ALPINE’S CDA-9887 TAKES ON HARSH ACOUSTICS

By CASEy THORSON

REVIEW

Experience music the way the artist intend­ed. That’s idea behind IMPRINT—a hard­ware/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 inten­tions. 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 envi­ronments 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 abun­dant amount of materials that reflect and absorb
sound, causing peaks and dips in music repro­duction. For instance, windows reflect and ampli­fy high frequencies. Leather-covered surfaces
like seats and hard plastic dashes and door
panels also reflect and change certain frequen­cies. 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 equaliza­tion 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 under­standing 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 informa­tion from the sound system within the acoustical
environment in order to identify the problems. It
then creates a set of equalization filters to cor­rect 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 opti­mize 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

everything together. This results in the smearing
of transients, ringing and comb filtering. In other
words, it muddies up the sound.

MultEQ filters are specifically designed to
address these time domain problems and con­centrate most of the signal energy in the direct
sound. Reflections thereby can be dramatically
reduced, allowing more pure sound from the
speaker to arrive at each seat. This dramatically
improves the soundstage because matched fre­quency response is one of the cues our ears rely
on for imaging.

Here’s what’s interesting. Whereas typical
time correction can only be applied to one chan­nel of an amplifier, MultEQ time corrects based
on frequency. This allows for time correction
between multiple drivers on the same channel,
not just the channel itself.

CDa-9887

Alpine’s CDA-9887 ($450) offers an impres­sive array of features. As the company’s top CD
player, the single-DIN head unit uses a 24-bit
Burr-Brown D/A converter and other leading
technologies. It’s also the company’s first head
unit equipped with the IMPRINT system.

The CDA-9887 supports MP3, WMA and AAC
playback and is also Satrad, Bluetooth and iPod
ready. Its detachable faceplate features a Biolite
display and that familiar Alpine look. Volume is
controlled through a rotary knob while buttons
flanking it and the display handle the remain­ing functions. Users can also use the supplied
remote to access basic functions.

The built-in DSP also allows a huge amount
of control. If you like to tweak your sound, you’ll
like this unit. It gives you six channels of time
correction, 3-way or 2-way crossover, seven­band graphic EQ or five-band parametric EQ and
MediaXpander.

Power is specified as 50 watts by 4, but if you
are looking for a full-feature unit like this, you’ll
probably be more interested in its three 4-volt
preamp outputs.

PrEParaTions

To access IMPRINT in the CDA-9887, either
become buddies with your Alpine retailer or
expect to shell out another $250. The extra
deuce-fifty will buy you the optional KTX-100EQ
IMPRINT Sound Manager. This includes both
the hardware go-between, a CD-ROM with
tuning software for a PC and the Measurement
Microphone.

Once the software has been loaded, it’s
go time. Drop the faceplate, shift it to the left
and remove—here users will find the IMPRINT
access port on the head unit. A cable connects
this port and the interface box, while a USB
cable connects the interface box to the PC. Plug
in the microphone and position it according to
the area selection—All, Front Left, Front Right,
Front or Rear. With the microphone in position,
click “Measure.” A series of “whoop” sounds will
burst from each speaker individually—a process
that takes about 4 to 5 minutes per area—for
all positions, expect to spend 40 minutes total.
That’s all the time it takes for the MultEQ func­tion of IMPRINT to fully analyze the acoustics of

the vehicle. Once finished, click the “Result” but­ton to view the Frequency and Time Response
graphs. You can then select from three target
curves for MultEQ to adjust its filter. Now the cor­rections can be saved to the CDA-9887.

I ran through these steps twice with different
mic positions. This provided two User Settings
to select between and compare to the default
settings.

PErfECTing sounD

Once satisfied with the MultEQ setting, I sat
down for a detailed listen. Straight away I noted
a big improvement over the unadulterated signal.
Easily notable was how much more linear the
frequency response was over the entire range.
Gone were the mild resonances of the low mid­range and the highs were quelled to a tolerable
level. But beyond the easily detectable items, the
system was markedly more precise. Snares were
sharper and cymbals crisper. The soundstage
was fuller with less clumping of the instruments—
a very welcome improvement.

While I was totally jazzed with what I was
hearing, I did find some things I didn’t like about
MultEQ. Even though I tried different mic posi­tions, the soundstage was always
the same—slightly pulled back and
a little low. On the positive, it was
somewhat correctable by fading to
the front. What bothered me more
was what I found while switching the
MultEQ between on and off; a small
amount of hiss was introduced into
the system while the feature was
engaged. It was also interesting that
MultEQ seemed to tailor the bass
somewhat with volume, much like
a loudness function would do—the
last quarter volume the bass tended
to come on a little strong.

Usability was also a bit disap­pointing. With the MultEQ on, you
cannot fine-tune the system. The
only options you are provided are to
adjust bass and treble, and balance
and fader—no crossovers, equaliza­tion or time alignment. There is also
the matter of only having three pre­determined target curves to select
from, each of which tapers toward
the high frequencies.

After listening with MultEQ, I tried

Above: This graph is part of the GUI for the IMPRINT Sound Manager. It shows

the measured frequency and time response of the system before and after the
correction filters were applied. Below: This screen shot shows the three
target curves users can select from.

my hand at tuning the system myself
using the vast DSP of the CDA-9887.
This meant measuring the speaker
distances relative to my seat posi­tion and setting the time alignment
as noted in the manual. From there
I fine-tuned the crossovers—select­ing the frequency, slope and output
level. I also opted to use the five­band parametric equalizer (over the
seven-band graphic EQ), which has
selectable (predetermined) frequen­cies, level and “Q” controls.

I compared my user-selected set­tings against the MultEQ filters. Even
though I spent a good part of two

hours playing with the adjustments, the 40 min­utes I spent learning and applying the MultEQ did
a far better job in respects to the tonal balance
of the system—with its 500 control points. It also
seemed to exhibit slightly better transients and
definition. On the other hand, I was able to tailor
the sound of the system more to my liking using
the user controls. I was able to improve certain
aspects of the soundscape over the MultEQ set­ting—whatever music I listened to came through
with greater depth and height and better right
channel information. I was impressed that I was
able to get the system to sound as good as it did
with only DSP in the head unit. But then again, I
had something respectable to compare it to.

EnD rEsulT

The CDA-9887 is rather remarkable. For $450,
it’s a nicely equipped head unit fit for both the
audiophile and everyday user. The DSP allows
for lots of tweaking and the IMPRINT technology
with MultEQ certainly makes tuning a vehicle
easy. The results are, to say the least, pretty
impressive. If you want to hear music close to
the way the artist intended, check out this Alpine
unit. It won’t disappoint.

Posted with permission from the April 2008 issue of Car Audio and Electronics ® www.caraudiomag.com. Copyright 2008, Source Interlink, Inc. All rights reserved.

For more information about reprints from Car Audio and Electronics, contact Wright’s Reprints at 877-652-5295.

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