VIII. Distributed lines

Example of a loadspeaker connected to a distributed line through a transformer

Part 2—CX Series Application Guide

With the helpful advice and input from contractors and consultants around the world, engineers at QSC designed the CX Series amplifiers to be a versatile and reliable foundation for high-quality installed sound systems.

This applications guide will help you design your sound system properly and utilize your CX amplifier(s) effectively.

The best way to distribute audio power from a common amplifier among numerous relatively low-powered loudspeakers is to use a distributed line, whether all the loudspeakers are meant to receive the same or different power levels.

A distributed line is usually referred to by its maximum voltage-

	25-, 70-, 100-, or 140-volt lines are most common. An amplifier’s	1.2W

		2.5W
	power rating is determined by how much current it can put out	2.5W

		5W
	at a standard voltage level; a low-power 70-volt amp has less	5W

	current capability than a high-powered 70-volt amp, even though	70V 10W
		70V 10W
	they can both put out the same voltage. The high-powered amp	COM
	can drive more speakers and at higher power levels than the	COM
	can drive more speakers and at higher power levels than the
	lower-powered one can. This is somewhat analogous to AC

electrical distribution, where you might have circuits rated for 15A, 20A, 30A, etc., at 120 or 240 VAC, and you can connect any

number of appliances to them as long as you don’t exceed the circuit’s current capacity.

COM

4.5V

	1.2W
	2.5W
	5W
70V	10W
Amplifier
0	COM

0.5W

16
8
4
COM	8

1.2W

2.5W

10W

COM

16	8
16
8
4
COM
	8

Loudspeakers on a distributed line use tapped transformers to match their power requirements to the line. A loudspeaker with a 70-volt trans- former tapped at 2 watts, for example, will receive that amount of power when the amplifier puts out 70 volts on the distributed line. Trans- former taps are usually set at 3 dB intervals, i.e.,

B each successive tap is twice the power level of its

predecessor. An example would be a transformer

tapped at 0.5, 1, 2, and 4 watts. This allows you

to select a power level that is most appropriate

	SPKR
Example of a 70 volt	COM
Example of a 70 volt
distributed line

for the situation while still retaining the versatil-

ity of configuring other loudspeakers on the same

line for different power levels.

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.

Part 2—CX Series Application Guide