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Hard rock. As a masonry contractor in Cambridge,
Massachusetts, Joe Sexton deals with it daily. Typically, Sexton supervises a group of 10
workmen at two to three construction sites in and around the Boston area. He's on the road
much of the day, hauling tools, bricks, and mortar in his 1996 Dodge Ram pickup.
When Sexton purchased his pickup in January, his
first thoughts were of hard rock – the kind he works with as well as the type of
music he listens to. His pickup is a working vehicle, exposed to jarring construction
sites, heavy loads, and lots of masonry dust. Since he spends so much time behind the
wheel, he wanted a sound system that could take the punishment and still meet his high
sonic standards.
Learning Curve
Almost immediately after purchasing the
truck Sexton was at the shop of his friend and installer Richard Inferrera, owner of'
Rich's CarTunes in Watertown Massachusetts. "Rich and I already had a strong
relationship," Sexton explained, adding that he also enjoys rap R&B, and other
forms of music in addition to rock. "He had installed sound systems in my two
previous vehicles. He knew what I liked and what I wanted – maybe even more than I
did."
"We had gone through a learning curve
on Joe's previous vehicles," Inferrera said. "Joe likes very loud, extremely
tight bass. He also wants a seriously dependable system because his pickup is a work
truck. He takes good care of his vehicles, but his truck takes a wicked-bad
pounding."
Besides the grueling working conditions,
Sexton and Inferrera had to consider security when designing a system. Sexton said his job
sometimes takes him to high-crime areas, and a highlighted audio system would be a red
flag to thieves looking for an easy target. Part of Inferrera's job was to effectively
hide an amp, CD changer, and multiple speakers in a space scarcely bigger than a
living-room sofa.
Rear Center Channel
From previous experience, Inferrera knew
that Sexton was a discriminating stereo customer with a well-tuned ear. Sexton prefers
strong front staging with plenty of rear fill. So for the Dodge Ram, Inferrera's design
began with two pairs of Dynaudio System 220 component speaker systems, which each
consist of two 5¼-inch midrange speakers, two 11/8-inch soft-dome tweeters, and a pair of
external crossovers. |
A midrange and
tweeter were installed in each door. The midrange was installed in the stock location at
the bottom of each door and covered by the built-in factory grille. A hole was cut near
the top of each door panel for each tweeter.
Another pair of midranges and tweeters was installed behind the seat in
carpet-covered enclosures. These speakers were aimed straight up at the ceiling of the
pickup. They were intentionally positioned close together to create a mono effect.
"We wanted to provide a strong rear
stage, but not diffuse separation from the front speakers," Inferrera explained.
"Full-size pickup trucks are very wide, and it's difficult to pull a center channel.
The rear speakers fill in nicely without overpowering the listener, and you still get
great left-and-right separation."
Sexton says the effect is like a set of
headphones. "It's a full surround sound for both the driver and passenger," said
Sexton, "very clean and intense. The performance is exactly that I was hoping
for."
The crossovers from the Dynaudio system
were mounted on the floor of the cab beneath the driver and passenger seat, two on each
side.
Bass In A Big Way
A pair of a/d/s/ RS12 12-inch
subwoofers are each mounted in a custom-built sealed enclosure, one on each side of the
mids and tweets behind the seat. The 1-cubic-foot enclosures are made of MDF
(medium-density fiberboard) and stainless steel and were tilted slightly upward to
correspond to the angle of the seat.
The subwoofer enclosures are covered with
carpet matching the truck's interior. They are also removable, which makes cleaning easier
and enhances security. "The location of the subwoofers provides an incredible bass
sensation," Inferrera noted. "You feel the bass in a big way."
There's not much room for a bank of
amplifiers in a standard pickup cab, so Inferrera's choice of amplifiers was limited to
models with enough power and versatility to handle this system's unique requirements. The
choice was an Xtant 3300c mounted on the back wall of the cab behind the midranges and
tweeters.
The 3300c is a distinctive three-channel
design, with two channels producing 60 watts each and a third channel cranking out 180
watts, all at 9 ohms. The third channel makes it possible to power a set of subwoofers
without bridging or using an electronic crossover. |
To prevent
overheating, the amplifier has a built-in cooling fan and the heatsink is wrapped in
Nomex, a heat-resistant material used in racing suits. A sensing circuit also regulates
power if it senses the amp is overheating.
Sexton said he likes the amp's numerous heat defense mechanisms because air
space is limited in his Ram pickup and the power demands are high. Another reason he chose
the 3300c is that it features a fully regulated PWM power supply, built-in electronic
crossover (with a 12-dB-per-octave slope), and a noise gate.
Make It Durable
The source unit selected for Sexton's Ram
had to provide equal measures of audio quality and durability. For that reason, Inferrera
and Sexton selected the Alpine CDA-7939 CD radio.
Under the seat is a six-disc Alpine
CHA-S605 CD changer. The S605 has an antivibration mechanism that uses silicon-oil dampers
for better shock absorption, an important feature given the rough conditions Sexton
encounters on the job.
The digital output of the CD changer is
routed to an a/d/s/ DA44 digital-to-analog converter. The DA44 is supposed to provide much
more accurate conversion of digital information from the CD than is possible from any head
unit, simply because head units are not large enough to house more sophisticated D/A
circuitry.
To give Sexton precise control over bass
frequencies, Inferrera's installation team added an a/d/s/ AC501 volume control under the
dash. The device allows the listener to adjust the gain on the bass to suit the music, the
environment, and personal preference.
Protection for the vehicle is provided by a
Clifford IntelliGuard 700-IQ security system. Inferrera also installed a Motorola mobile
phone with hands-free operation, and a remote starter.
Rock Solid
Inferrera said the installation, which
required more than two weeks of work, was among the most elaborate pickup-truck systems
his crew had ever designed. "Joe is a very discriminating customer," said
Inferrera. "He's very particular about his vehicles and he expects excellent
workmanship. We knew from past experiences with his vehicles what he was expecting."
Conversely, Sexton said Inferrera has
helped him appreciate car audio. "Rich helped me realize that a great car stereo can
make the driving experience much more enjoyable," he said. "The sound of my new
system is unbelievable." |
