Ecler EPC7000 Manual De Instrucciones página 5

STEP BY STEP THROUGH THE EPC7000
REDUCED DIMENSIONS AND WEIGHT HIGH PERFORMANCE
In the last ten years, the evolution of professional sound systems has been certainly
influenced by two facts: The reduction of acoustic cabinet size and the ever increasing output
power of amplifiers. Systems are now lighter, smaller and more portable, while the sound
quality approaches more and more that of a Hi-Fi system. Electronics is the key of this
advances. The components generally called "processors" are able to push a sound system to its
limits. These intelligent electronic systems, sometimes contained in the amplifier itself, but in
most cases mounted into dedicated processor units, constantly monitor the systems operating
conditions. The result is a total reliability as far as the systems behaviour is concerned, which is
the main obsession when installing professional sound systems.
THREE-WAY SYSTEMS: THE PERFECT SOLUTION
This is the optimal system to achieve faithful voice and music reproduction. It's a fact
that the human ear is more sensible in the central portion of the audible spectrum, which
enables us to easily recognize any kind of irregularity in this frequency range. This justifies the
need for a dedicated driver for the reproduction of the human voice, which ranges from 200 to
1500 Hz).
The overall structure of the EPC systems is based on two cabinets: The first one only
reproduces the lowest frequencies below 150 Hz, while the second one reproduces both the
midrange (from 150 Hz to 1500 Hz) and the high frequencies (from 1500 Hz to 22 kHz).
HYBRID BASS-REFLEX-TYPE CABINETS
This groundbreaking enclosure is the result of combining conventional bass-reflex
philosophy and a diffusion system half the way between direct radiation and a folded horn
structure.
The massive excursion subbass speakers must suffer bring up important distortion. This
distortion is caused by the fact that the voice coils often move far away from their rest
position. Thus, the magnetic flux density gets reduced. The bass cabinets in the EPC7000
system use two electrically phase-inverted parallel mounted 18'' (45,7 cm) drivers. One driver
is mounted in opposite direction. With this configuration, when the voice coil of the first driver
moves forward, the second voice coil moves backwards, resulting in a remarkable cancellation
of second-order harmonic distortion and a slight cancellation of third-order distortion. A very
clean sound and an excellent "cone control" are consequently obtained even in critical
situations. It has to be considered that conventional subwoofers at high output levels may
reach up to 10 % distortion.
Each loudspeaker is mounted into a separate acoustic enclosure, including a dedicated
port. This reminds "transmission line" systems. The angled position of the drivers and the
separation wall share similarities with folded horn-loaded systems. The implemented solution is
in fact a bass-reflex concept with a certain port Q value in the way between pure direct
radiation and horn radiation, using the advantage of both worlds.
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