User manual ELECTRO-VOICE CH230WX DATASHEET

[. . . ] Things are generally a little calmer over in our audio-only remote trucks. We usually deal only with the music elements. Of course, that may mean 10 bands in a row!Our Classic Silver Studio has the big Neve VR with recall and Flying Faders snapshots, and that works well when you have time to reset. [. . . ] Allow me to explain some of the "sound innovations" behind the DVX concept, at the drawing board stage and beyond. Woofers, like all loudspeakers, are governed by a complex melding of disciplines: mechanical engineering, electrical engineering, physics and acoustics. The DVX line has been optimized in all of these areas using the latest technologies. First of all, the DVX magnet structure, the motor that works with the voice coil to provide the drive force to the woofer, was optimized for strength, stability, travel and linearity. Nonlinearity in a speaker's magnetic field or suspension not only leads to added distortion but also greatly impacts the life expectancy of a speaker. For example, if you have a speaker motor that is stronger when the cone is moving out of the basket than when moving in, the speaker will tend to offset itself to the outside. Since the suspension of the speaker (the surround and the spider) can only move a finite distance in either direction before being damaged, you are going to stress these components more in one direction than the other. It also makes the speaker limit (stop moving) too quickly in one direction, and that means you lose sensitivity and increase distortion. To further compound this problem, the magnetic field generated by the voice coil can cause the field of the permanent magnet to modulate. This is the (continued on page 66) Come Out on the Road Efficiency and Accuracy By Design Electro-Voice DVX Woofers by Alan Babb T he DVX Series is the latest generation of high-performance woofers from Electro-Voice (EV). The story begins in spring 2005, when EV launched its ZX5 as the "world's most versatile loudspeaker": a 2-way portable powerhouse capable of filling large spaces with concert-quality sound, all while weighing in at less than 50 pounds. In speaker terminology, we call that hunk of iron a "pole piece"; every speaker has one. Most people understand the problems caused by inductance at high frequencies. Engi- Graph plotting the variation in the strength of the magnetic field in the motor gap vs. time, using a DVX motor structure and a conventional ceramic motor structure. Drive signal: 75V pk at 100 Hz. neers take advantage of inductance all the time in crossover design. The problem with inductance in a speaker is as follows: As the cone moves outward, it moves out of the magnetic circuit and the pole piece is no longer inside as much of the coil as when the cone is moving inward. This asymmetry in the inductance also causes an offset of the speaker's center position, just like a nonlinear magnetic field or suspension. Besides negatively impacting the life expectancy of a speaker, this asymmetry causes distortions that are particularly audible and offensive. To combat this problem, the DVX woofer uses multiple approaches. First, we computermodeled the magnetic structure and optimized the geometry to eliminate asymmetries. After the FEA phase prototyping, the tests and measurements began. [. . . ] Rehearsal time for live shows can be short or nonexistent. Getting titles for classical music movements without a score, improvisational jazz, or artists and production people that won't give up a set list (or who even change it without telling audio), and these days, even guns on stage are all elements that make obtaining this information difficult. I would be very interested to hear from you post guys about what you like to see for documentation. What happens to the paper documentation? [. . . ]