Mackie M1400/M1400i Contactor's Specs (M1400) - Page 5

frequency boost to compensate for the natural roll-off inherent in all compression drivers. Some speaker manufacturers provide external processors with plug-in modules for each of the various combinations of horns and drivers (at an additional cost to you!) to compensate the CD horns. Each channel of an FR Series power amplifier has its own built-in CD horn compensation circuit. All you need to do is set the variablefrequency horn EQ control on the amplifier to the manufacturer's recommended mass breakpoint frequency (the point where the frequency response begins to roll off). As an added feature, if you're not using CD horns, set the frequency control fully clockwise to the AIR setting to enjoy Mackie's exclusive AIR EQ, a gentle high-frequency boost that brightens and lightens the sound. Low-cut filter. Virtually all loudspeakers have a low-frequency cutoff point somewhere above 20Hz. Many low-frequency drivers have a -3dB point at 35Hz to 40Hz, while many stage monitor speakers cut off at about 100Hz; there's no sense in amplifying low- frequency signals that the loudspeaker cannot reproduce. Each channel of the FR Series amplifiers has a continuously variable low-cut filter. Simply dial in the frequency at which the loudspeakers drop off (anywhere from OFF to 170Hz), and reap the benefits of saving amplifier power with cleaner, tighter bass. Built-in subsonic stabilizer. Even with the low-cut filter set to the OFF position, each channel of the FR Series amplifiers has a built-in subsonic stabilizer (technically called infrasonic stabilizer). This dampens the very low frequencies, which can be caused by microphone handling or stage rumble. These frequencies are below the threshold of human hearing, and rob the amplifier of power and contribute to intermodulation distortion. Protection circuits. Both amplifiers are equipped with a number of unique and innovative protection circuits to ensure the safety of your speakers and the amplifiers. Separate left and right Protect LEDs on the front panel indicate when a protection circuit has been activated. For example, when the amplifier is first turned on the outputs are muted for three seconds, during which time the Protect LEDs are lit. This allows time for all the equipment in the system to power up and stabilize, and prevents potentially damaging thumps or pops from propagating to the speakers. Separate left and right Short LEDs indicate if there is a short circuit at the speaker output terminals. This lets you know at a glance to check the speaker wiring for shorts (or recalculate the speaker load impedance) right from the get-go, so you don't waste precious time searching for the problem. Combined left and right Cold and Hot LEDs indicate if the amplifier has overheated. Under normal operation, the Cold LED remains lit. If the Hot LED should light, the outputs become muted until the amplifier cools to a safe operating temperature, then normal operation ensues. The FR Series: The most affordable, full-featured power amplifiers available. As you can see, there is every reason the M•1200 and M•1400 are fast becoming the premier affordable choice for many sound reinforcement and recording applications. With their proven durability, professional features and specs, and certainly not least, low cost - the FR Series is destined to be a classic. There are no other power amplifiers in their class with all these features at such an affordable price. And that's why people from all professions, with all kinds of different applications, prefer Mackie's FR Series. You'll like them because of their low price, easy-to-use features, and rugged construction. That's got to sound good. And, of course, Mackie does. 5