User manual QSC AUDIO MD POWERED

[. . . ] 1675 MacArthur Blvd. , Costa Mesa, CA, 92626 USA Main Number (714) 754-6175 or toll free (USA only) (800) 854-4079 Customer Service(714) 957-7150 or toll free (USA only) (800) 772-2834 MD Series Powered Loudspeaker Products User Manual MD-FP122/64r MD-FP122/66 MD-FP122/94r MD-FP122/96r MD-FP122/124r MD-FP152/64r MD-FP152/66 MD-FP152/94r MD-FP152/96r MD-FP152/124r 60° x40° (HxV) 60° x 60° 90° x40° 90° x 60° 120° x40° 60° x40° 60° x 60° 90° x40° 90° x 60° 120° x40° 12-inch, two-way 12-inch, two-way 12-inch, two-way 12-inch, two-way 12-inch, two-way 15-inch, two-way 15-inch, two-way 15-inch, two-way 15-inch, two-way 15-inch, two-way *TD-000186-00* TD-000186-00-D Important Safety Precautions & Explanation of Symbols Install in accordance with QSC Audio Product's instructions and under the supervision of a licensed Professional Engineer. WARNING! CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE THE COVER. The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of uninsulated "dangerous" voltage within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to humans. The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in this manual. 5- WARNING: To prevent fire or electric shock, do not expose this equipment to rain or moisture. [. . . ] · Overheating should correct itself within 1-2 minutes, after which sound should resume. See below for a full explanation of thermal protection. · Short periods of muting indicate a component fault. In this case AC power should be removed and the speaker serviced. Momentary Bright Red Flashes · During operation, bright flashing indicates clipping (overdrive distortion). · This is normally due to excessive volume, and will likely be accompanied by audible distortion. · If the speaker mutes repeatedly during peaks, there may be a component fault. AC power should be removed and the speaker serviced. Continuous Half-bright Light · Indicates that the internal limiter is reducing gain, due to prolonged clipping and/or excessive temperature. · After several seconds of severe clipping, the limiter will reduce power to protect the speaker and improve the sound. This results in a steady, half-bright red indication. Any further clipping will still result in bright flashes on top of the steady half-bright indication. When the program level is reduced, the limiter will clear after several seconds, and the red indicator will go out. · If the power module overheats, the first response is to trigger limiting, to reduce volume and limit further temperature rise. This results in a steady half-bright illumination that does not clear even after reducing program level. It may take several minutes for temperature to drop and clear the limiter. During this time, the exposed heat sink will feel uncomfortably hot to the touch. If overheating continues, the amplifier will ultimately mute, resulting in a full-bright red indication. When muting clears, the amplifier will resume operation, with thermal limiting still active until it further cools off. · Overheating is usually caused by excessive ambient temperature, since the internal temperature rise of the Class-D power module is relatively low. Protect the speaker from excessive temperatures, such as being placed over a heater vent, or allowing direct sunlight to impinge upon the heat sink surface. 6 Location of Pick Points There are fifteen (15) load-rated pick points on the MD enclosure; four each on the top and on the bottom, two each on the sides, and three on the rear of the enclosure. These pick points are indicated with arrowheads on the illustration. Note the pick points on the cabinet bottom are not shown, but are identical to those indicated on the cabinet top. As shipped from the factory, each pick point has a strength rated flat head bolt installed. [. . . ] 2- Coverage: Included angle between -6dB points, plus X, minus Y dB, 500 to 3. 2k Hz, taken at ISO preferred one-third octave intervals, or for an otherwise specified frequency range. 3- Directivity Index (DI): Difference between on-axis SPL and average SPL (considering all axes) for the specified coverage range. DI= 10 log Q 4- Directivity Factor (Q): Directivity index expressed as a power ratio Q=10 exp DI/10 5- Amplifier Power: The maximum sustained power at less than 1% clipping, averaged over the intended frequency range, 6- Input Sensitivity: The sine-wave input voltage required to reach amplifier clipping, measured within the frequency range used to determine Maximum Peak SPL, with the gain on "normal" and no gain reduction due to limiting. 7- Input Headroom/Clipping: Maximum input voltage. [. . . ]