QSC Audio 1200 Power Capacity, Power Limiting, User Responsibility, RMS Power Ohm 16-ohm Load

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You may have some problems finding the larger value capacitors in the preferred film-type construction. If necessary, several can be paralleled; simply add the individual capacitances together to get the total rating. You will probably have to locate non-polar electrolytics for values greater than 10-20uf.

4.4POWER CAPACITY

All speakers have a maximum long-term power limit which is determined by the temperature rise of the voice coil. The speaker can withstand short peaks above this level, since the voice coil takes a little while to overheat. The time lag depends on the size and mass of the voice coil and ranges from a fraction of a second to several seconds. The required speaker rating for a given amplifier power depends on the type of program material. Extreme cases such as lead guitar work may require speaker ratings of twice the RMS power of the amplifier to withstand the full peak power. The average power of signals where some attempt is made to prevent overdrive distortion will be less than the amplifier RMS rating; how much less depends on the dynamic range and headroom allowance. In live-performance situations where feedback and high-energy artists can push the system to its limits, it would probably be wise to match the RMS ratings of the speakers and the amplifiers.

4.5POWER LIMITING

There are several ways to limit the power to safe levels without operator intervention. Some speaker systems have protective circuits, or at least fuses. Fuses can be added which will blow in case of overloads; the problem is to select a fuse with the correct time lag and overload characteristics to match the speaker limitations. The speaker manufacturer is in the best position to specify these values; the following table is presented for rough guidance only. The fuse values shown are calculated for fast-blow fuses, which will carry 135% of their rating for an hour, and which blow within 1 second at 200% current. The RMS power rating shown is correlated to 135% of the fuse current. The fuse voltage is not critical; 32 volt fuses should have the lowest resistance which will avoid loss of damping factor.

RMS Power

4-ohm

8-ohm

16-ohm

 

Load

Load

Load

30w

2.0

1.5

1.0

50w

2.5

1.6 or 2.0

1.25

75w

3.0

2.0 or 2.5

1.5

100w

4.0

2.5

1.6 or 2.0

200w

5.0

3.0 or 4.0

2.5

400w

7.5

5.0

3.0 or 4.0

Table 4.5 Fuse Ratings (values in amps)

The power may also be limited with active circuitry. QSC offers a plug-in Octal PowerLimit Module (PL-1) which can be adjusted to put a ceiling on the power level; the circuit acts to reduce volume as necessary to keep the power below the desired ceiling. The PL-1 lets you set the power ceiling independently for each channel, without the interruptions of fuse protection. Please contact the QSC Sales Department for specific information on the Octal Modules.

4.6 USER RESPONSIBILITY

Remember that your Series One amplifier has extra peak power (dynamic headroom) in reserve. Observe the hook-up and operating precautions. QSC is not liable for any damage to loudspeakers caused by overpowering, wrong-frequency operation or electronic faults.

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Contents Owner’s Manual Avis SafeguardsPrecautions B L E O F C O N T E N T SOverview of Amplifier Warranty and DisclaimersIntroduction WelcomeFrequency Response SpecificationsInput Impedance Crosstalk Controls Indicators Cooling 1100 1200 1400 1700II Basic Instructions Important PrecautionsUnpacking and Inspection Quick Instructions Back View Front ViewCooling III OperationInput Connections AC RequirementsSee illustrations in .3 for location 34a 1/4-inch RTS Balanced Output Connection 36 1/4-inch Quasi-balanced Output Connection Input Switches and Mono Bridging Octal Module AccessoriesSpeaker Connections Mono Bridge Precautions69 Speaker Wire Table Cable Power Loss Damping Length Gauge ResistanceFactor Output Protection Features73 70 Volt Output Power 25 and 70 Volt SystemsNo Sound Operational TroubleshootingUnwanted Noises Horn Driver Protection IV Speaker ProtectionBackground DC ProtectionUser Responsibility Power CapacityPower Limiting RMS Power Ohm 16-ohm LoadObtaining Service Maintenance and ServiceCleaning User MaintenancePage D I O

1200, 1700, 1400, 1100 specifications

QSC Audio has long been a revered name in professional audio, and its series of amplifiers—including the QSC 1100, 1200, 1400, and 1700—continues to showcase the brand's commitment to quality, performance, and innovation. Each model is designed to meet the diverse needs of audio professionals, whether for live sound, installations, or studio use.

The QSC 1100 amplifier is renowned for its lightweight and compact design while delivering a solid 1100 watts of power. It features QSC's advanced Class D technology, which not only provides high efficiency but also significantly reduces heat generation. The 1100 includes comprehensive protection circuitry, ensuring safe operation in all situations. With a Frequency Response of 20 Hz to 20 kHz, the amplifier offers a balanced and clear sound profile, making it suitable for various applications.

Moving up the line, the QSC 1200 offers increased power output at 1200 watts and comes equipped with advanced DSP (Digital Signal Processing). The DSP allows users to tailor the audio output precisely, delivering optimized performance for any setting. In addition to its robust power, the 1200 features a versatile input section, supporting both XLR and 1/4" TRS connectors, providing flexibility for any audio source.

The QSC 1400 amplifier is a workhorse in the series, capable of producing up to 1400 watts, making it ideal for larger venues and events. This model is designed with enhanced thermal management, ensuring reliability even during extended use. The 1400’s high-frequency response capabilities further improve its adaptability, handling complex audio signals with ease.

Lastly, the QSC 1700 stands as the powerhouse of this lineup, delivering a remarkable 1700 watts of clean, distortion-free audio. It boasts an advanced cooling system, making it perfect for high-demand environments. The 1700 is also equipped with customizable limiter settings, allowing users to protect their speakers while maintaining sound integrity.

QSC’s commitment to durability is evident in all four amplifiers, featuring rugged chassis designs and high-quality components to withstand the rigors of professional use. Collectively, the QSC 1100, 1200, 1400, and 1700 amplifiers offer a compelling range of features that cater to various audio needs, all while ensuring superior sound quality and reliability, making them excellent choices for any sound engineer or venue manager.
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