3.0Designing an EVF/EVH Cluster

3.1General Aiming and Placement Guidelines

Loudspeakers should be “pointed at the people” and away from reflective room surfaces. Since people are excellent absorbers of sound and room surfaces are often not, this practice insures not only that the audience will receive the high frequencies necessary for good voice intelligibility and musical clarity but also that the reflective surfaces do not energize the room with intelligibility-robbing reverberation.

Loudspeakers for sound reinforcement are usually located high above a stage or platform and aimed down and out into the audience. This minimizes the difference between the longest throws to the rear of a venue and the shortest throws to the front rows, promoting coverage uniformity. Note that the typical portable loudspeaker on a short, 6-foot stand cannot duplicate such uniformity since the distant seats are so much farther away than the front rows. The direct sound from a loudspeaker drops 6 dB every time the distance from it doubles, according to the formula:

Level loss (dB) = 20log10(closest distance/farthest distance).

See comments on the audibility of different dB differences in section 3.4 Coverage-Uniformity Target.

3.2 Choosing between the EVF Full-Range and the EVH Full-Range Systems

When the reverberation time of a room (formally called T60 and the time it takes sound, once the source has stopped, to decay by 60 dB) exceeds 2-2.5 seconds at mid frequencies, the horn-loaded EVH series should be used. The EVH’s low-frequency horn mouth is large enough to control the rated coverage pat- tern down to 500 Hz, which promotes clarity by keeping more sound off of reflective surfaces than can the smaller, 12-inch-square horns and direct-radiating woofers of the EVF series. This concept is explored in more detail below.

3.21 Directivity Break Frequency Defined

Below a certain frequency, the mouth size of a waveguide is no longer large enough to maintain the nomi- nal coverage angle and the coverage angle gets wider and wider as frequency is decreased. The fre- quency at which this occurs is called the “directivity break frequency” (fb) and is inversely proportional to the size of the waveguide mouth and the nominal coverage angle of the waveguide. The directivity break frequency can be approximated by the following formula:

fb (Hz) = 1,000,000/[angle (degrees) x dimension (inches)].

Electro-Voice EVF/EVH User Manual

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Electro-Voice EVF-2121S, EVH-1152S, EVF-1152D Designing an EVF/EVH Cluster, General Aiming and Placement Guidelines
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EVH-1152S, EVF-1152S, EVF-1122S, EVF-1122D, EVF-1152D specifications

Electro-Voice is renowned for its high-quality audio solutions, and the EVF series embodies this commitment. The EVF-2121S, EVF-1121S, EVF-1181S, EVF-1151S, and EVF-2151D are a collection of loudspeakers designed for a variety of professional audio applications, each with its distinctive features and capabilities that cater to different sound reinforcement needs.

The EVF-2121S is a dual-12-inch full-range speaker that combines exceptional power handling with a wide frequency response. It utilizes a coaxial driver arrangement, providing even sound distribution and a cohesive audio experience. This model is ideal for medium to large venues, offering a robust SPL (sound pressure level) output and clear reproduction of vocals and instruments.

In contrast, the EVF-1121S features a single 12-inch driver, delivering precise, high-impact sound suitable for smaller spaces. Its design emphasizes clarity and detail, making it perfect for live sound applications. The compact and lightweight design also ensures ease of transport and installation, appealing to mobile sound reinforcement professionals.

The EVF-1181S is a dedicated subwoofer that amplifies low frequencies, featuring an 18-inch woofer for deep, powerful bass response. Its extended low-frequency output enhances the overall sound experience, making it an ideal choice for high-energy music events and professional club environments. Designed with rugged construction and efficient power handling, the EVF-1181S is built to withstand demanding conditions while delivering reliable performance.

The EVF-1151S combines a 15-inch woofer with an advanced high-frequency driver for a full-range sound that works well in theatres, concert halls, and corporate events. The speaker ensures clear mid and high frequencies, maintaining vocal intelligibility even in challenging acoustic environments.

Lastly, the EVF-2151D is a dual 15-inch subwoofer that enhances overall system performance with its ability to produce deep bass. Its compact enclosure design allows for seamless integration into various sound setups, ensuring it can meet the needs of both portable and installed sound systems.

All models in the EVF series incorporate advanced technologies, including proprietary transducers and custom-engineered waveguides, which contribute to their impressive performance. With features like durable enclosures and efficient power handling, these loudspeakers are engineered to provide reliable sound reinforcement for both live and recorded applications. Whether it’s a concert, event, or installation project, the Electro-Voice EVF series stands out for its versatility and audio excellence.
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