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SUPERIOR PERFORMANCE PARAMETERS for the new VPC units were strategically
balanced so that low resonant frequencies could be achieved along with high sound
Cone mass is held to a minimum for high efficiency yet its Acrylic Resin
pressure levels.
Laminate (ARL) design yields tremendous rigidity. The lighter the cone the easier it is for
the magnet to move it in and out; therefore, higher sound pressure levels for a given
amount of amplifier power input. Additional loudness is achieved through longer cone
travel so we designed the PC units with 0.25 to 0.35 inches (6-8 mm) of peak-to-peak
excursion which is rarely found in component woofers of this price range.
INCREDIBLY FLEXIBLE INSTALLATION is the real benefit to the new Pro Components. The
PC woofers perform well in sealed, vented, and bandpass boxes. Due to the low resonance
values, they also work quite well in infinite baffle installations where the woofer is mounted
on the rear deck of a car and uses the trunk for its enclosure.
The best investment in system design is planning time. Before building
completely draws building plans. Although small modifications are often made throughout
construction, 99% of the home is built as planned. Exactly the same attitude must be
followed in the design of a car audio system and we therefore refer to it as "System
Architecture".
MULTI-WAY SYSTEMS
Although a simple head-unit with four
speakers will provide reasonable sound, a
really good system almost always requires
some kind of subwoofer. In order to
include the subwoofer speakers a dividing
network must be installed that keeps the
low frequencies out of the midrange
speakers. "Two-way " "crossovers" have a
crossover point set of 80 to 100 Hz for
example. You can go crazy with additional
crossover points and amplifiers (three-way,
five-way, etc.) but these should be left to
the better retail installers or high-end
hobbyists.
SOUND QUALITY VS. SPL
A well designed sound system can provide good sound quality and still play loud. Above
about 120 dB (decibels) the sound isn't perceived as getting much louder due to the non-
linearities of the human ear. A loudspeaker with reference value of 90 d8 1 watt/l meter
will usually offer about 11 O-l 15 dB inside a car if driven by an amplifier of about 100 watts
(more than enough for most listeners).
Good sound quality is achieved when a system offers several sonic attributes. IMAGING is
the accurate rendition of instrument placement which can only be achieved with proper
loudspeaker placement. STAGING is an extension of imaging where a perceived listening
event is recreated with well defined height, width, and depth as with an actual sound
stage. Correct FREQUENCY RESPONSE implies that all frequencies within the range of
human hearing (20-20 kHz) are audible and balanced in relation to one another. TIMBR
(pronounced Tam-bur') is the system's ability to reproduce the sound signature of a tru
so that it doesn't sound like a trombone. LINEARITY is the systems ability to provide
consistent frequency response regardless of volume setting. Some systems sound "shrill"
at high levels if the tweeters are over driven. They may also sound weak at low volumes
due to our psychoacoustic hearing effects which we perceive bass loss at low levels.
a house an architect
CROSSOVER
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