User manual MACKIE SR1521Z

[. . . ] SR1521Z 2-WAY ACTIVE LOUDSPEAKER SYSTEM USER'S MANUAL IMPORTANT SAFETY INSTRUCTIONS 1. Install in accordance with the manufacturer's instructions. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat. Do not defeat the safety purpose of the polarized or grounding-type plug. [. . . ] This results in increased reliability and longevity for the amplifier. The amplifier module is mounted on a large heatsink, which is cooled by convection where cool air is drawn through it's fins, carrying the heat away. In order for this convection cooling to work efficiently, it is important to provide adequate airspace behind the loudspeaker. When you position the SR1521z, we recommend leaving at least six inches of air space behind it. In the unlikely event of the amplifier overheating, a built-in thermal switch will activate, which mutes the signal and lights the THERMAL LED. When the amplifier has cooled down to a safe operating temperature, the thermal switch resets itself, and the SR1521z resumes normal operation. If the thermal switch activates frequently, try turning down the level control a notch or two on the mixing console (or the back of the SR1521z) to avoid overheating the amplifier. If the temperature in the room is too high, it could cause the amplifier to overheat. In this case, you should try aiming a fan at the rear panel to move more air through the heatsink fins. · · · · AC POWER Be sure the SR1521z is plugged into an outlet that is able to supply the correct voltage specified for your model. If the voltage should drop below 97% of the specified line voltage, the built-in amplifiers will no longer be able to supply rated power. (They will continue to operate down to 80% of the rated line voltage, but won't reach full power, resulting in lower headroom. ) Be sure the electrical service can supply enough amperage for all the components connected to it. We recommend that a stiff (robust) supply of AC power be used because the amplifiers place high current demands on the AC line. The more power that is available on the line, the louder the speakers will play and the more peak output power will be available for cleaner, punchier bass. A suspected problem of "poor bass performance" is often caused by a weak AC supply to the amplifiers. Never remove the ground pin on the power cord of the SR1521z or any other component. This is very dangerous. SERVICE INFORMATION Warranty Service Details concerning warranty service are spelled out on page 11 of this manual. If you think your loudspeaker has a problem, please do everything you can to confirm it before calling for service, including reading through the following Troubleshooting section. Doing so might save you from being deprived of your Mackie loudspeaker. Of all Mackie products returned for service (which is hardly any at all), many are coded "CND" -- Could Not Duplicate-- which usually means the problem lay somewhere else in the system. The following troubleshooting tips may sound obvious, but here are some things you can check: Poor bass performance · Check the polarity of the connections between the mixer and the loudspeakers. You may have your positive and negative connections reversed at one end of one cable, causing one loudspeaker to be out-of-phase. Poor sound · Is it loud and distorted?Make sure that you're not overdriving a stage in the signal chain. [. . . ] The address of your closest authorized service center will be given to you by Technical Support. IMPORTANT: Make sure that the Service Request Number is plainly written on the shipping carton. LOUD Technologies reserves the right to inspect any products that may be the subject of any warranty claims before repair or replacement is carried out. LOUD Technologies may, at our option, require proof of the original date of purchase in the form of a dated copy of the original dealer's invoice or sales receipt. [. . . ]