Electro-Voice EVC-1122-VIBTEN54, Руководство по установке

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EVC Variable-Intensity Loudspeakers Introduction | en 5
Electro-Voice Installation manual 2019-10 | 04 | F.01U.378.116
2 Introduction
EVC-1122-VI Variable Intensity loudspeaker
The EVC-1122-VI Variable Intensity loudspeaker is a two-way design with a unique compound
waveguide that can evenly cover a defined rectangular audience area with almost no variation
in sound quality and minimal change in level.
The high frequency section the EVC-1122-VI comprises a single 1¼-inch pure titanium dome
compression driver directly coupled to a specialized waveguide that combines the
functionality of long-throw and short-throw horns in a single acoustic device. The low
frequency section employs a high-output woofer that was developed using state-of-the-art,
computer-aided optimization to provide low distortion, high efficiency, and maximum
intelligibility at high sound pressure levels. The passive crossover implements an enhanced
fourth-order design with slopes of greater than 24 dB per octave for smooth off-axis response
and improved definition through the critical vocal range.
The EVC-1122-VI enclosure is constructed of 15-mm plywood and finished with EVCoat for
enhanced durability. The loudspeaker has been designed with M10 suspension points as well
as attachment points for an optional U-bracket. EVC series loudspeakers accept wire gauges
up to 10 AWG.
Constant directivity vs variable intensity
Most modern loudspeaker systems designed for installation are based on a constant-
directivity approach. They are designed to provide a consistent, smooth transition from the
low-frequency woofer to the high-frequency section. Constant-directivity systems typically
have symmetrical vertical coverage patterns and constant horizontal coverage. Systems built
around single or multiple constant-directivity loudspeakers are widely used in high quality
installed sound reinforcement systems. While many implementations deliver excellent
performance, one key drawback is that SPL can vary significantly over the audience area - from
front-to-back and left-to-right. The front-to-back variation can be minimized by tilting the horn
further back or by adding appropriately delayed fill speakers, but these remedies often result
in noticeable slap echo, decreased dynamic range, and poor intelligibility because of excessive
excitation of the reverberant field.
The EVC-1122-VI attacks these shortcomings by producing a wide near-field coverage angle
and a narrow far-field angle from a single loudspeaker system. The 12-inch woofer is installed
in the enclosure at an angle so that its central axis is directed toward the last row of the
audience, using the natural off-axis roll-off the driver to deliver more consistent level to every
seat. And the unique, asymmetrical waveguide replaces a short-throw/long-throw horn
combination to evenly cover the audience area with a single device. The resulting coverage
characteristic ensures a well-defined rectangular listening area, and the more gradual intensity
change compensates for the drop in SPL over the longer distance to the back of the room. The
size of the coverage area is determined by the height at which the loudspeaker is mounted, as
well as the vertical angle at which the system is aimed. This single-box solution reduces
material costs and labor time while increasing performance with higher intelligibility and more
uniform coverage.
In summary, the major advantages of the EVC-1122-VI are:
–
Rectangular coverage pattern . Traditional waveguides deliver an elliptical pattern to the
floor. VI horns deliver a rectangular pattern, which helps to fill in the corners of the room.
No more costly delay lines.
– Even SPL front-to-back . The unique, patented throat and flare structure of the VI
waveguide delivers more consistent sound levels throughout the room, eliminating ear
strain at the back of the seating area and painful ears at the front.