QSC Audio CX Series user manual How Many Speakers?, Watts for the speakers, 25 x 1.25 =

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X. How Many Speakers?

How many loudspeakers can you connect to the distributed line? The amplifier itself determines the amount of audio power available to the line, and from that figure you must compensate for insertion loss in the speaker transformers and for headroom when you determine how much power is available

1.56watts for the speakers.

 

 

 

…+25% for

For example, let’s suppose you have an amplifier rated at 500 watts into a 70-volt

 

 

 

headroom.†

line, and your speaker transformers each have an insertion loss of 1 dB, which is

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.25 watts

typical. The losses in the transformers mean that they will draw 25% more audio

 

 

…approx. 1/4 watt

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

more to compensate

 

 

 

 

power than they deliver to the speakers. For headroom, as mentioned before, you

 

 

for transformer

 

 

 

 

add at least another 25% to the total amount of power drawn from the amplifier.

 

 

insertion loss*

 

 

1 watt

 

 

 

 

 

 

 

 

 

 

The additional 25% headroom is optional but highly recommended. It will allow

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

for future additions to the system and reduce the stress on the power amplifier.

 

 

 

 

 

 

 

 

 

 

 

 

1.25 x 1.25 = 1.5625

 

 

For every watt put

 

 

 

 

 

So you’ll need at least about 56% more power than the total sum of the transformer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

into the speakers,

 

 

 

 

taps. The reciprocal of 1.5625 is .64, so conversely you can figure on allowing a

 

 

 

you need…

 

 

 

 

maximum of 64% of the amplifier’s rated power for the loudspeakers. Therefore,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the highest combination of transformer taps the 500-watt amplifier can drive

 

 

 

 

 

 

 

 

 

 

 

 

satisfactorily is a sum of about 320 watts, e.g., 32 speakers each tapped at 10 watts,

 

 

 

 

 

 

 

 

 

 

 

 

or 64 speakers tapped at 5 watts, etc.

 

 

 

 

 

 

 

 

 

 

 

 

This table lists the recommended maximum load (sum of all speaker transformer

*assuming a typical insertion loss of 1dB

power taps on one line) for the CX6T and CX12T amplifiers. These figures assume

†a good engineering practice

a typical transformer insertion loss of about 1 dB.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

You can, of course, use different output configurations on

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the two amp channels if it’s not operating in bridged mono

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

mode. For example, one channel of a CX12T could drive a

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

70-volt line loaded at 320 watts while the other channel

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

drives a 25-volt line, or even a direct loudspeaker.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Contents CX Series Table of Contents Explanation of Graphical Symbols Speaker Damage Rack Mounting PrecautionsLifting Precautions Speaker Output Shock HazardII. Overall Description Portable rackCX4 Input Sensitivities III. InputsIV. Outputs Caused by a floating inputOutput connections for CX, bridged mono mode VI. Operation AC PowerControls & Displays CX4 and CX4TTroubleshooting CX6, CX6T, CX12 and CX12TProblem Overheating CX6, CX6T, CX12 & CX12TPage BRIDGED-MONO Mode Caution CX4 and CX4TMaximum LONG-TERM Output Power AC Current ConsumptionHeat Emissions Protection Circuits Damping Factor VII. SpecificationsFrequency Response Output RegulationInput SENSITIVITY, Vrms Power RequirementsVoltage Gain Input ImpedanceDimensions WeightLine for different power levels VIII. Distributed linesLoudspeaker Coverage and Placement IX. Designing the Distributed Sound SystemPage Requires Determining Power LevelsIntelligibility Selecting the Amplifier ExampleUsing Components with Different Voltages 25 x 1.25 = How Many Speakers?Watts for the speakers Or 64 speakers tapped at 5 watts, etcXI. Other Design Considerations Speaker Transformer SaturationWire Loss Power Transfer Coefficient = RLOAD/RWIRE + RLOAD2Page Heat Emissions XII. Address & Telephone Information

CX Series specifications

QSC Audio, a recognized leader in professional audio solutions, presents the CX Series of amplifiers, a fusion of power, efficiency, and cutting-edge technology designed to meet the demands of various sound reinforcement applications. Known for their reliability and outstanding performance, the CX Series amplifiers are perfect for installations in venues, theaters, and houses of worship, delivering high-quality audio reproduction regardless of the setting.

At the core of the CX Series is its robust Class D amplification. This technology not only ensures excellent audio fidelity but also enhances energy efficiency, resulting in lower operational costs and cooler running temperatures. The amplifiers utilize a linear power supply, which contributes to exceptional audio quality by providing stable and clean power to the components. With varying power ratings, including options ranging from 200 to 1200 watts per channel, the CX Series caters to different venue sizes and specific audio requirements.

The CX Series is engineered with a range of features that enhance usability and performance. Integrated DSP (Digital Signal Processing) allows users to access advanced sound processing algorithms, enabling fine-tuning of audio settings for optimal performance. The amplifiers include comprehensive protection circuitry to safeguard the equipment from thermal overload, short circuits, and signal clipping, ensuring longevity and reliability in demanding environments.

Connectivity is also a significant aspect of the CX Series. The amplifiers are equipped with a variety of input and output options, including XLR, 1/4" TRS, and barrier strip connectors, facilitating seamless integration with a wide range of audio sources and speakers. Moreover, the user-friendly interface includes LCD displays for easy monitoring, making setup and adjustments straightforward for audio engineers and technicians.

Another defining feature of the CX Series is its lightweight design. This portability makes installation and transport easy without compromising on performance. Additionally, QSC’s commitment to sustainability is evident in the design, as the amplifiers are constructed with environmentally friendly materials and have a reduced carbon footprint, aligning with modern practices in eco-conscious audio engineering.

In summary, the QSC Audio CX Series amplifiers blend professionalism with versatility, delivering exceptional performance that satisfies both audio quality and operational reliability. Their innovative technologies and thoughtful design make them a powerful ally for professionals in any sound reinforcement scenario.
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