QSC CX-4 Brochure

PRELIMINARY SPECIFICATIONS

CX4

FEATURES

Automatic Two-Speed, High
Efficiency Fan Cooling—For Quiet
Normal Operation with Maximum
Cooling on Demand

Rear-to-Front Air Flow—
Keeps Equipment Racks Cool

Front Panel Status LED’s—
Indicate Clip and Power

Rear Panel Detented Gain
Controls—For Security and
Resetability

Detachable Euro-Style Barrier
Strip Input—Easy and Economical
Connections

Double Thickness Rack Ears—
For Extra Strength

Covered Barrier Strip Output
Connections—Meets Safety
Agency Requirements

The CX4 amplifier is ideal for use in any permanently
installed sound system. Designed to meet the spe­cialized needs of high power, high quality audio
systems, the CX4 offers the features requested
most by contractors and installers from around the
world. Rear panel gain controls offer extra security
and front panel status LEDs offer easy indication of
the amplifier conditions. Per channel power ratings
of 150 watts at 8 ohms, 225 watts at 4 ohms and

LOAD OUTPUT POWER

20Hz-20kHz, 0.1% THD 1 kHz, 1% THD

Stereo (W/Ch)

8Ω 150 watts 170 watts
4Ω 225 watts 250 watts
2Ω 350 watts*

Mono-Bridged

16Ω 300 watts 340 watts

8Ω 450 watts 500 watts
4Ω 700 watts*

350 watts at 2 ohms make the CX4 an economical
choice for direct output applications that don’t
require the output transformers of the CX4T. The
CX4 resides in a rugged two rack-space steel chassis
approximately 17.9 inches deep. High output
power, high thermal capacity and rugged reliability
make the CX amplifiers ideal for any high perfor­mance sound system installation.

*typical

1675 MacArthur Boulevard
Costa Mesa, California 92626-1468 USA
Phone: [phone] Fax: [phone]

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POWER OUTPUT

Direct output, watts per channel, both channels driven

8Ω, 20 Hz-20 kHz, 0.1% THD 150
8Ω, 1 kHz, 1% THD 170
4Ω, 20 Hz-20 kHz, 0.1% THD 225
4Ω, 1 kHz, 1% THD 250
2Ω, 1 kHz, 1% THD* 350

Direct Outputs, bridged mono

8Ω, 20 Hz-20 kHz, 0.1% THD 450
4Ω, 1 kHz, 1% THD* 700

*typical

DISTORTION SMPTE-IM, less than 0.05%

FREQUENCY RESPONSE 20 Hz-20 kHz, +0.2 dB

DAMPING FACTOR 200

NOISE 100 dB below rated output (20 Hz to 20 kHz)

VOLTAGE GAIN 35x (31 dB)

INPUT SENSITIVITY, VRMS

for rated power, 8Ω 0.96

INPUT IMPEDANCE not less than 20 Kohms

CONTROLS

Front: AC Switch
Rear: Ch.1 and Ch. 2 Attenuator Knobs
(11 detents: 0, -2, -4, -6, -8, -10, -12, -14, -18, -24, off)

FRONT PANEL/INDICATORS (per channel)

CLIP: Red LED
POWER: Green LED

REAR PANEL/CONNECTORS (each channel)

Input: Euro-style detachable header
Output: Covered barrier strips

COOLING 2-speed fan, with back-to-front air flow

AMPLIFIER PROTECTION

Output Averaging™ short circuit protection, open circuit, ultrasonic, RF, thermal muting
Stable into reactive or mismatched loads

LOAD PROTECTION Turn-on/turn-off muting, DC-fault

OUTPUT CIRCUIT TYPE Class AB complementary linear stage

POWER REQUIREMENTS: 100, 120, 220-240 VAC, 50/60 Hz

POWER CONSUMPTION

Normal operation: 1/8 power @ 4Ω per channel
Worst case continuous program: 1/3 power @ 2Ω per channel
Maximum: full power @ 2Ω per channel
Multiply current by 0.5 for 220-240 VAC operation

FPO/BACK

ARCHITECT’S AND ENGINEER’S SPECIFICATIONS

The amplifier shall contain all solid-state circuitry, using complementary
silicon output devices in a Class AB output circuit. The amplifier shall op­erate from 50-60 Hz AC power, with internal taps for selecting voltages
100,120, or 220-240 VAC. The amplifier shall operate from a normal
household AC outlet, drawing less than 500 VA when driven with random
program material at 1/8 rated power into four ohm loads. The amplifier
shall be supplied with a single molded AC cord having an appropriate AC
plug for the intended operating voltage.

The amplifier shall employ forced-air cooling with a two speed fan for
minimum acoustic noise. Air flow shall be from rear to front to avoid tem­perature rise inside the rack. Rack mounting shall be possible without
clearance necessary between amplifiers for ventilation. The amplifier
shall be capable of continuous operation at 1/8 power, into four-ohm
loads, for ambient temperatures up to 104 F (40 C).

The amplifier shall contain two independent channels, with separate AC
transformer secondaries, power supplies, and protection systems. All
protection systems shall be self resetting upon removal of fault, and the
remaining channel shall continue to operate. Each channel shall have in­dependent protective circuitry against open circuit, short circuit, or mis­matched loads. Each channel shall monitor temperature of its heat sink
and shall trigger fan speed boost, and if necessary, signal muting to pre-

vent excessive temperature rise. Each channel shall have on-off muting,
acting for three seconds after turn-on, and within 1/4 second after turn­off or loss of AC power. Each channel shall have DC fault protection for
the load. Fault fuses shall be adequately large to prevent nuisance blow­ing at any output power the amplifier is capable of delivering.

Each channel shall have the following controls and displays: A rear panel
Gain control and front panel displays consist of a green LED power-on
indicator and a red LED showing true amplifier clipping. The output con­nectors for each channel shall be shrouded barrier strip connectors. The
standard input panel shall provide detachable Euro-style header connec­tions for each channel. Inputs shall be electronically balanced, with a
minimum impedance of 10 kilohms per side, and a common mode rejec­tion of at least 50 dB from 20 Hz to 20 kHz.

Each channel shall be capable of meeting the following performance cri­teria with both channels driven: Sine-wave output power of 150 watts
into eight ohms, and 225 watts into four ohms, 20 Hz to 20 kHz, with less
than O.1% THD. Frequency response at 3 dB below rated power shall be

+

0.2. dB. The voltage gain shall be 35, equivalent to 31 dB, and

within
the input sensitivity shall be 0.96 V
range of 20 Hz to 20 kHz shall exceed 100 dB. IHF damping factor shall
exceed 200.

The amplifier chassis shall occupy two rack spaces, with provision for se­curing the rear corners. Depth from mounting surface to tips of rear sup­ports shall be 17.9" (45.5 cm).

Weight shall not exceed 30 Ibs. (13.6 kg). The amplifier shall be the QSC
Audio Products Model CX4.

. The signal to noise ratio over the

RMS

DIMENSIONS

Faceplate Width Standard 19" (48.3 cm) Rack Mounting
Chassis Depth 17.9" (45.5 cm) deep (to rear support ears)
Faceplate Height 3.5" (13.3 cm)

WEIGHT Shipping–36 lb; 16.4 kg; Net–30 lb; 13.6 kg

1675 MacArthur Boulevard • Costa Mesa, California 92626-1468 USA • Phone: [phone] Fax: [phone]