Mackie SRM650 Owners Manual - Page 14

SRM550/SRM650 Powered Loudspeakers Smart Protect AC Power There are advanced DSP protection mechanisms designed into the SRM550 and SRM650 to safeguard the loudspeakers and amplifiers from inadvertent damage. The protection circuits are designed to protect the loudspeakers under reasonable and sensible conditions. Should you choose to ignore the warning signs [e.g. excessive distortion], you can still damage the speaker by overdriving it past the point of amplifier clipping. Such damage is beyond the scope of the warranty. Limiting The driver has its own compression circuit which helps protect it from damaging transient peaks. The compressor is designed to be transparent and is not noticeable under normal operating conditions. Overexcursion Protection Be sure the SRM loudspeaker is plugged into an outlet that is able to supply the correct voltage specified for your model. It will continue to operate at lower voltages, but will not reach full power. 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 a 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 or any other component of the SRM loudspeaker. This is very dangerous. An 18 dB/octave high-pass filter just prior to the low-frequency amplifier prevents very low frequencies from being amplified. Excessive low-frequency energy can damage the woofer by causing it to "bottom out," also know as overexcursion, which is equivalent to a mechanical form of clipping. Thermal Protection All amplifiers produce heat. SRM loudspeakers are designed to be efficient both electrically and thermally. In the unlikely event of the amplifier overheating, a built-in thermal switch will activate, muting the signal. When the amplifier has cooled down to a safe operating temperature, the thermal switch resets itself, and the SRM loudspeaker resumes normal operation. If the thermal switch activates, try turning down the level control a notch or two on the mixing console (or the back of the loudspeaker) to avoid overheating the amplifier. Be aware that direct sunlight and/or hot stage lights may be the culprit of an amplifier overheating. Care and Maintenance The SRM550/SRM650 loudspeakers will provide many years of reliable service if you follow these guidelines: • Avoid exposing the loudspeakers to moisture. If they are set up outdoors, be sure they are under cover if rain is expected. • Avoid exposure to extreme cold (below freezing temperatures). If you must operate the loudspeakers in a cold environment, warm up the voice coils slowly by sending a low-level signal through them for about 15 minutes prior to high-power operation. • Use a dry cloth to clean the cabinets. Only do this when the power is turned off. Avoid getting moisture into any of the openings of the cabinet, particularly where the drivers are located. 14 SRM550/SRM650 Powered Loudspeakers