Introduction - Electro-Voice EVC-1122-VIB Installation Manual

EVC Variable-Intensity Loudspeaker
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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. It can be used as a full-range system or as a
mid-/high-frequency enclosure matched to the EVC-1181S subwoofer. EVC loudspeakers are
voiced so that they can be seamlessly used in systems with other EV-Innovation models (EVA,
EVF, and EVH), so the EVC-1122-VI can be used in conjunction with any of these, including the
other two-way systems in the EVC series.
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. The input panel also accepts optional covers with NL4-type connectors or
weatherized gland-nuts.
For 70V/100V operation, the input panel has an internal landing pad for mounting EV's high-
quality TK-150 audio transformer. When the transformer is installed, it engages EV's patented
Automatic Saturation Compensation (ASC), which preserves low frequency performance while
presenting a stable load to the amplifier - regardless of the number of speakers connected in
parallel. As a result, EVC loudspeakers - including the subwoofers - sound virtually identical,
whether they are used with a transformer or without.
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
2018.01 | 01 | F.01U.345.997 Installation manual Electro-Voice