User manual ELECTRO-VOICE 644 DATASHEET

[. . . ] 11 3. 4 Coverage-Uniformity Target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3. 5 Multiple-Source Interference in Clusters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3. 51 Reducing Multiple-Source Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4. 0 Preparing EVF and 644 Systems for Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Rotate and reinstall the contours in the top and bottom of the enclosure. Reinstall the grille. Electro-Voice EVF/644 User Manual 19 4. 0 Preparing EVF and 644 Systems for Installation (cont') Figure 12: An 644 hard foam waveguide contour being removed for reorientation 4. 5 Digital Signal Processing 4. 51 Full-Range Systems in Passive Mode For full-range systems in the passive mode, the internal crossover/equalizer network sends low frequencies to the woofer and high frequencies to the compression-driver/waveguide combination. In addition, the network tailors the frequency response and levels of each individual driver so that the overall frequency response of the loudspeaker is essentially flat over its design operating range. Once a cluster of EVF and/or 644 systems is installed in a venue, a digital signal processor (DSP) will typically be used to adjust the in-room frequency response, based on the specifics of the situation. In addition, the DSP should be used to provide the high-pass filters recommended to protect EVF and 644 systems against overdrive at frequencies below their operating range. Failure to do so could damage the low-frequency drivers if fed high-level signals below the system's operating range. Table 3 shows the recommend high-pass filter frequencies for infrasonic protection of EVF and 644 systems. Different highpass filter frequencies are recommended for some fiberglass versions based on changes in operation range due to the effects of having a sealed enclosure. Model(s) EVF-1122S/XX EVF-1152S/XX EVF-1121S EVF-1151S EVF-1181S 644-1152S/XX Recommended High-Pass Frequency (minimum) 65 Hz 45 Hz 50 Hz (55 Hz for Fiberglass Versions) 35 Hz (55 Hz for Fiberglass Versions) 33 Hz (45 Hz for Fiberglass Versions) 60 Hz Table 3: Recommended high-pass frequencies for infrasonic protection of EVF and 644 systems 20 Electro-Voice EVF/644 User Manual 4. 0 Preparing EVF and 644 Systems for Installation (cont') 4. 52 Using the EVF-1121S and EVF-1151S Low-Frequency Systems in Full-Range Clusters that Operate on a Single Power-Amplifier Channel The EVF-1121S and EVF-1151S low-frequency systems have integral passive low-pass filters that roll off frequencies above 100 Hz at the rate of 12 dB per octave. This means that these systems can be used to augment the low-frequency output of the EVF-1122/XX and EVF-1152/XX full-range systems without the use of an external digital signal processor (DSP) for crossover from the low-frequency to the full-range systems. As many as two full-range systems can be paralleled with an EVF low-frequency system on a single power-amplifier channel capable of driving a 2. 1-ohm minimum impedance. This simplified, cost-effective configuration is most appropriate for applications that require only moderate or moderately high acoustic output. It has six holes that fit a standard 5/8-inch shackle (user supplied). Both the VRK and the HRK rigging plates use arrow designators and a series of letters by each of the mounting holes to ensure that the desired angle is achieved. Refer to Tables 5, 6, and 7 for a description of the appropriate arrow direction and letter. All rigging plates except the EVF-to-EVF-subwoofer rigging plates are symmetrical, meaning that the mounting-hole layouts are the same from the left to the right sides of the rigging plate. The EVF-to-EVFsubwoofer rigging plates are asymmetrical, meaning that one side is for subwoofers, labeled "Sub, " and the other side is for EVF's, labeled "EVF. " This rigging plate must be flipped over depending on which side the subwoofer is on. All user-supplied hardware must be overhead load-rated (using applicable safety factors) for the specific cluster. See section 6. 0 for additional details on load limits and safety factors. 5. 2 EV-I Rigging Primer The following sections describe the clustering of EVF and 644 systems using one of the following three approaches: 1. EBK-M10 eyebolt kits supplied with each system (used in conjunction with other user-supplied hardware). Optional VRK vertical rigging kits, in conjunction with the supplied EBK eyebolt kits and user-supplied hardware. Optional HRK horizontal rigging kits, in conjunction with the supplied EBK eyebolt kits and user-supplied hardware. [. . . ] Lifting Hoists: Prior to each use, inspect the lifting hoist(s) and associated hardware (including motors, if applicable) for any cracks, deformation, broken welds, corrosion or missing or damaged components that could reduce the hoist strength. Never exceed the limitations or maximum recommended load specified by the hoist manufacturer. Always follow manufacturers' recommendations for operation, inspection and certification. Always raise and lower the load slowly and evenly, avoiding any rapid changes in speed or shifting loads that could result in a sudden jolt to the suspended system or the structure from which it is suspended. [. . . ]