QSC Audio CX Series user manual Wire Loss, Power Transfer Coefficient = RLOAD/RWIRE + RLOAD2

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speaker, it will affect the sound level from the distributed line’s speakers also, possibly altering them from your intended levels.

An alternate method is to attach an 8-ohm speaker across the 25-volt outputs. This provides up to approximately 80 watts to the speaker and makes more power available to the 70V or 100V connections: up to 75 watts for the CX4T, up to 150 watts for the CX6T; up to 400 watts for the CX12T.

WIRE LOSS

Even the highest-quality copper wire has a small amount of resistance to electrical current flow, and the wire’s resistance is inversely proportional to the cross-sectional area of its conductor. Therefore, to minimize the power lost to speaker cable resistance, you should use the largest stranded (always stranded) copper wire that is practical for the job. This is especially important with direct low-impedance speaker connections; e.g., a half- ohm wire resistance would not affect a lightly-loaded 100-volt line noticeably, but it would reduce the amount of power going to a 2-ohm load by 36%, a 1.9 dB drop. It would also reduce the damping factor to no better than 4.

If an amplifier could drive a speaker load through theoretical zero-resistance wire, no power would be lost in the speaker cables. In the charts below we’ll compare the power delivered through real-world speaker cables with the theoretical zero-resistance ideal and express it as a ratio called the power transfer coefficient. It is determined by the formula

POWER TRANSFER COEFFICIENT = [RLOAD/(RWIRE + RLOAD)]2

Let’s say you have an 8-ohm speaker load. With that imaginary zero-resistance wire, all the power would be delivered to the load, so the power transfer coefficient would be 1. If you then substituted wire with 0.2 ohm of resistance, the load would only get 95.2% of the power it got with the zero-ohm wire, so the power transfer coefficient would be 0.952 (a loss of 0.2 dB, by the way).

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Contents CX Series Table of Contents Explanation of Graphical Symbols Rack Mounting Precautions Lifting PrecautionsSpeaker Damage Speaker Output Shock HazardII. Overall Description Portable rackCX4 III. Inputs IV. OutputsInput Sensitivities Caused by a floating inputOutput connections for CX, bridged mono mode AC Power Controls & DisplaysVI. Operation 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 VII. Specifications Frequency ResponseDamping Factor Output RegulationPower Requirements Voltage GainInput SENSITIVITY, Vrms Input ImpedanceDimensions WeightLine for different power levels VIII. Distributed linesLoudspeaker Coverage and Placement IX. Designing the Distributed Sound SystemPage Intelligibility Determining Power LevelsRequires Selecting the Amplifier ExampleUsing Components with Different Voltages How Many Speakers? Watts for the speakers25 x 1.25 = 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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