User manual MACKIE SRM450

[. . . ] SRM450 ACTIVE SOUND REINFORCEMENT SPEAKER USER'S MANUAL CAUTION AVIS 8. Heat -- This Mackie product should be situated away from heat sources such as radiators, or other devices which produce heat. Power Sources -- This Mackie product should be connected to a power supply only of the type described in these operation instructions or as marked on this Mackie product. Power Cord Protection -- Power supply cords should be routed so that they are not likely to be walked upon or pinched by items placed upon or against them, paying particular attention to cords at plugs, convenience receptacles, and the point where they exit this Mackie product. [. . . ] · Avoid placing loudspeakers against a wall. This, too, increases the low frequency output, though not as much as corner placement. However, if you do need to reinforce the low frequencies, this is a good way to do it. · Avoid placing the active speakers directly on a hollow stage floor. A hollow stage can resonate at certain frequencies, causing peaks and dips in the frequency response of the room. It's better to place the active speakers on a sturdy table or tripod stands. · Position the active speakers so the highfrequency drivers are two to four feet above ear level for the audience (make allowances for a standing/dancing in the aisles audience). High frequencies are highly directional and tend to be absorbed much easier than lower frequencies. By providing direct line-ofsight from the active speakers to the audience, you increase the overall brightness and intelligibility of the sound system. · Highly reverberant rooms, like many gymnasiums and auditoriums, are a nightmare for sound system intelligibility. Multiple reflections off the hard walls, ceiling, and floor play havoc with the sound. Depending on the situation, you may be able to take some steps to minimize the reflections, such as putting carpeting on the floors, closing draperies to cover large glass windows, or hanging tapestries or other materials on the walls to absorb some of the sound. However, in most cases, these remedies are not possible or practical. Making the sound system louder generally doesn't work because the reflections become louder, too. The best approach is to provide as much direct sound coverage to the audience as possible. The farther away you are from the speaker, the more prominent will be the reflected sound. Use more speakers strategically placed so they are closer to the back of the audience. If the distance between the front and back speakers is more than about 100 feet, you should use a delay processor to time-align the sound. (Since sound travels about 1 foot per millisecond, it takes about 1/10 of a second to travel 100 feet). RIGGING The SRM450 cabinets are fitted with ten rigging points as shown in the diagram below. M10 threaded eyebolts (M10 x 1. 5 mm x 20 mm) are available to fit these inserts (PA-A1 Eyebolts). WARNING: Never attempt to suspend the SRM450 active speakers by their handles. If you want to suspend them, use the rigging points only. [. . . ] If you bring your loudspeaker to an Authorized Service Center and they can't find anything wrong with it, you may be charged a service fee. If the Authorized Mackie Service Center is located in another city, pack the loudspeaker in its original shipping carton. More information on packing can be found in the Service section of this manual. Contact the Authorized Mackie Service Center to arrange service or bring the loudspeaker to them. [. . . ]