valutazioni - 3, GPA: 4.7
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Facilità d'uso
Features The variable-Q active filter sets used in the EQ-231 allow effective equalization with few problematic side effects. As Figure 1 illustrates, the filter characteristics vary with the amount of boost or cut used. At low control settings, the filter Q is very wide. As the control is boosted or cut, the filter Q narrows so that there is minimum interaction between adjacent frequency bands. Each of the 31 1/3-octave filters per channel provides 12 dB of boost or cut at ISO frequencies 20 through 20,000 Hz (see Figure 2). The faders have a positive detent in the center, flat-response position. The gain control also has a center detent at unity gain. It should be adjusted so that the adjacent peak LED rarely or never lights. This will help achieve maximum possible signal- to-noise ratio. The infrasonic low-cut filter, with a 43-Hz corner frequency and a slope of 18 dB per octave, is engaged by the front-panel Lo-Cut switch (see Figure 3). For most applications, the filter should be engaged. Most professional speaker systems have little output below 45 Hz. At best, driving them in this range wastes amplifier power, and can result in excessive, ultra-low-frequency cone motion which distorts the output in the reproduced frequency range and, most seriously, could damage the speaker from excessive cone motion or “bottoming.” The range select switch allows selection of either 6 or 12 dB of boost and cut on either channel. The 6-dB range will allow more control selectivity while the 12-dB range allows for greater range of adjustment. The EQ-231 has an IEC connector to allow compatibility with ac connections anywhere. The integral fuseholder also doubles as the voltage selector to allow for operation anywhere in the world. Figure 5 shows front and rear panel details. Architects’ and Engineers’ Specifications The equalizer shall have 31 filters for each channel centered at the ISO standard 1/3-octave frequencies between 20 and 20,000 Hz. The filters shall provide either 6 or 12 dB of boost or cut and be set by 22.5-mm linear controls. The front panel shall have the following controls: a gain control that is continuously variable from -12 dB to +12 dB from unity gain; a high-pass filter with a slope of 18 dB per octave and a corner frequency of 43 Hz; a range switch to select either 6 or 12 dB of boost or cut from the filters; an EQ-on switch to put the filters in the signal path and an on/off switch. The rear panel shall have the input and output connectors, a ground-lift switch and a IEC connector with an integral fuse holder that allows voltage selection by the way it is inserted. The inputs and outputs of the equalizer shall be accessible via 3-pin XLR-type and 1/4-inch TRS phone jacks located on the rear of the unit. The input shall be actively balanced. The output shall be balanced on the 3-pin XLR-type plug. EQ-231/Graphic Equalizer EQ-231/Graphic Equalizer EQ-231/Graphic Equalizer The equalizer shall meet or exceed the following performance specifications: frequency response at unity gain, …1 dB 20 20,000 Hz; total harmonic distortion less than 0.01%, 20 - 20,000 Hz at 0 dBu; a noise level of less than -97 dBu; gain of ±6 dB or ±12 dB; balanced-input impedance of 44,000 ohms; output impedance of 120 ohms; a maximum input level of +20 dBu at unity gain; a maximum output level of 20 dBu into loads greater than or equal to 600 ohms. The equalizer shall operate on 120 V/240 V ac, 50/60 Hz, and consume less than 18 watts. The unit shall be operable over the temperature range as high as 50 degrees Centigrade or 122 degrees Fahrenheit. The chassis shall be steel with a gray front panel and black top, bottom, sides and back with white nomenclature. The chassis shall occupy one rack space in a standard 19-inch rack (height: 3.46 inches; depth: 9.24 inches; width: 19 inches). The weight shall be 8.8 lb (4.0 kg). The equalizer shall have a three-year parts and labor warranty. The equalizer shall be the Electro-Voice EQ-231. Limited Warranty Electro-Voice products are guaranteed against malfunction due to defects in materials or workmanship for a specified period, as noted in the individual product-line FIGURE 1 — Filter Response at Different Slider Positions Showing Q of Filter Changing. statement(s) below, or in the individual product data sheet or owner’s manual, beginning with the date of original purchase. If such malfunction occurs during the specified period, the product will be repaired or replaced (at our option) without charge. The product will be returned to the customer prepaid. Exclusions and Limitations: The Limited Warranty does not apply to: (a) exterior finish or appearance; (b) certain specific items described in the individual product-line statement(s) below, or in the individual product data sheet or owner’s manual; (c) malfunction resulting from use or operation of the product other than as specified in the product data sheet or owner’s manual; (d) malfunction resulting from misuse or abuse of the...