CMX Series User Manual CMX 300V CMX 500V CMX 800V TD-000322-00-B *TD-000322-00*
IMPORTANT SAFETY PRECAUTIONS AND EXPLANATION OF SYMBOLS WARNING! The lightning flash with the arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of uninsulated “dangerous” voltage within the product’s enclosure that may be of sufficient magnitude to constitute a risk of shock to humans. The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operation and maintenance (servicing) instructions in this manual. 1.
Warranty (USA only; other countries, see your dealer or distributor) Disclaimer QSC Audio Products, LLC is not liable for any damage to amplifiers, or any other equipment that is caused by negligence or improper installation and/ or use of this loudspeaker product.
Introduction These rugged, fan-cooled, 2-channel, 2RU amplifiers provide high-value performance and power in a strong, compact chassis. The series comprises four models: the CMX 300V, CMX 500V, CMX 800V and CMX 2000V. The CMX 2000V is covered in a separate manual. Features • Independent, user-defeatable clip limiters • Fully selectable low-frequency filtering; choice of 30 or 50 Hz roll-off • Stereo (dual-channel), parallel-input, or Bridge Mono operating modes • Balanced inputs — XLR, ¼" (6.
Back Panel 1. Barrier strip input 7. Terminal block connector outputs, Channels 1 and 2 2. XLR inputs, Channels 1 and 2 8. Circuit Breaker 3. Configuration dip switches 9. Serial number label 4. TRS inputs, Channels 1 & 2 10. Configuration switch chart 5. Fan 11. IEC power inlet (power cord connector) 6.
Input Filter What it is The low-frequency (LF) filter rolls off signals below either 30 Hz or 50 Hz (Figure 6 and 7). This improves bass performance by limiting sub-audio cone motion, making more power available for the speakers' rated frequency range. The filter settings for each channel are controlled individually through the DIP switch settings shown in (Figure 4). When the filter is turned off (Figure 5), a 5 Hz roll off protects against DC or deep sub-audio inputs.
Parallel Input Mode What it is The Parallel Input switches let you operate the amplifier in Parallel mode, delivering the same signal to both channels without using a Y cable. Each channel drives its own speaker load, with independent gain, filtering, and clip limiting. Set switch positions 4 and 5 to "PARALLEL INPUTS" to couple the inputs together (Figure 8). Turn the switches to "STEREO" for stereo, bi-amping, or other 2-channel modes.
Bridge Mono Mode What it is Bridge Mono mode combines the power of both amp channels into one speaker, resulting in twice the voltage swing, four times the peak power, and approximately three times the sustained power of a single channel. This mode uses Channel 1's input, attenuation control, input filter, and clip limiter; Channel 2's dip switch settings should be in the OFF position, the attenuation control should be at maximum attenuation (Figure 10 and 11).
The Difference Between Modes Stereo Mode Stereo mode is the typical way of using the amplifier. Each channel is fully independent. Separate signals connect at the inputs, the attenuation knobs control their respective channels, and separate speakers connect to each output. The dip switches are set as shown in (Figure 14), a schematic illustration in (Figure 15). Examples: • Two-channel (stereo) playback. • Two independent mono signals, such as main and monitor mixes.
Bridge Mono Mode This mode combines the full power capabilities of both channels into a single speaker system. The amplifier internally re-configures so that both channels operate as a unit. This delivers double the output voltage, resulting in four times the peak power and three times the sustained power into a single 8 or 4Ω speaker load. The Bridge Mono mode section on page 7 describes the special speaker connection used.
Channel 1 input Channel 2 input not used Channel 1 signal input Channel 2 No input! Can be used to Daisy-chain additional amplifiers Amplifier #2 input – Figure 19 – Distributed Constant Voltage Outputs 70 Volt Operation: CMX 300V CMX 500V CMX 800V The CMX 300V and 500V must be configured for Bridge Mono mode for 70 Volt operation. Please refer to the above section on Bridge Mono mode for proper setup configuration.
Installation Rack mounting of the amplifier is optional. Use four screws and washers when mounting the amplifier to the front rack rails. Support the amp at the rear also, especially in mobile and touring use; rear rack mounting ear kits are available from QSC’s technical services department or by special order from your dealer or distributor. Use the dimensions (Figure 20 and 21 ) for planning. Side view 15.75" 400 mm 15.60" 396 mm 15.35" 390 mm 15.23" 387 mm 15.10" 384 mm 3.0" 76.
Connections Inputs Each channel has active balanced XLR and ¼" (6.3 mm) inputs wired in parallel (Figure 22). The input impedance is 20 kΩ balanced, 10 kΩ unbalanced. Balanced signals are less prone to AC hum, but unbalanced signals can be suitable for short cable runs. The signal source’s output impedance should be less than 600Ω to avoid high frequency loss in long cables. Balanced Inputs Use the XLR or ¼" (6.3 mm) TRS input jacks, or the barrier strip (Figure 25).
Speakon™ Outputs CMX amplifiers offer a choice of output connections, with two Neutrik NL4MD Speakon™ jacks and a Terminal Block connector. The Speakon™ connector is designed specially for high-power speaker connections. It locks in place, prevents shock hazard, and assures the correct polarity. The upper Speakon™ jack has both Channel 1 and Channel 2 outputs, so it is especially useful for Parallel, bi-amp, or Bridge Mono mode operation (see Bridge Mono mode operating precautions on page 7).
Terminal Block Connector The terminal block connector requires the following assembly. 1. Strip the wires to 7 ~ 8 mm. 2. Insert the wires into the male part of the connector according to the Mode you are using. See below. 3. Use a flat-tip screwdriver to secure the wires. Tighten the screws to 6 in.-lbs. 4. Insert the plug into the receptacle on the amplifier. 5. Use a flat-tip screwdriver to secure the connector. Tighten the screws to 6 in.-lbs.
Operating Voltage (AC Mains) Make sure you connect the amplifier to the correct AC line voltage, as shown on the serial number label. Connecting to the wrong line voltage is dangerous and may damage the amplifier (Figure 31). – Figure 31 – Operation AC Power Switch Before applying power, check all connections and turn the attenuation controls fully counter clockwise to maximum attenuation. One second of muting is normal when the amp is turned on or off (Figure 32).
Fan cooling The fan speed varies automatically to maintain safe internal temperatures. Keep the front and rear vents clear to allow full air flow. Hot air exhausts out the front of the amp so it does not heat the interior of the rack. Make sure that plenty of cool air can enter the rack, especially if there are other units which exhaust hot air into it. Safe operating levels The amp's protective muting system guards against excessive internal temperatures.
Indication: CLIP LED flashing If the red CLIP indicator flashes when signal is applied, the amplifier output may be shorted. Check the speaker wiring for stray strands or breaks in the insulation. Indication: CLIP LEDs bright and steady The amplifier is in protective muting. One second of muting is normal when the amp is turned on or off. Overheating will cause protective muting.
Specifications CMX 300V CMX 500V CMX 800V Stereo Mode (both channels driven) 8Ω / FTC 20 Hz - 20 kHz / 0.1% THD 8Ω / EIA 1 KHZ / 0.1% THD 4Ω / FTC 20 HZ - 20 KHZ / 0.1% THD 4Ω / EIA 1 KHZ / 0.5% THD 2Ω / EIA 1 KHZ / 1% THD 70 V - Direct drive / EIA 1 kHz / 1% THD 185 W 200 W 280W 300 W 430 W - 260 W 300 W 400 W 500 W 700 W - 450 W 500 W 650 W 800 W 1200 W 400 W Bridge Mono Mode 8Ω / FTC 20 Hz - 20 kHz / 0.1%THD 8Ω / EIA 1 kHz / 0.
Mailing Address: QSC Audio Products, LLC 1675 MacArthur Boulevard Costa Mesa, CA 92626-1468 USA Telephone Numbers: Main Number: (714) 754-6175 Sales & Marketing: (714) 957-7100 or toll free (USA only) (800) 854-4079 Customer Service: (714) 957-7150 or toll free (USA only) (800) 772-2834 Facsimile Numbers: Sales & Marketing FAX: (714) 754-6174 Customer Service FAX: (714) 754-6173 World Wide Web: www.qscaudio.com E-mail: info@qscaudio.com service@qscaudio.com © 2010 QSC Audio Products, LLC.
