Qsc Cmx500v User manual

User Manual

CMX 300V

CMX 500V

CMX 800V

CMX Series

*TD-000322-00*

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. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

WARNING: To prevent ﬁre or electric shock, do not expose this equipment to rain or moisture. Do not use this apparatus

near water.

5. Clean only with a dry cloth.

6. Allow a minimum of 6" (152 mm) clearance behind cabinet for convection cooling. Keep anything that might restrict airﬂow from the rear

of the enclosure (i.e. draperies, fabric, etc.). Do not block any ventilation opening. This product is a power ampliﬁer that produces heat.

7. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including ampliﬁers) that produce heat.

8. Do not defeat the safety purpose of the grounding-type plug on the three-pronged “Edison” style power cable. The grounding plug has

two blades and a grounding prong. The third prong is provided for your safety. If the provided plug does not ﬁt your outlet, consult an

electrician for the replacement of the obsolete outlet. Do not cut off the grounding plug or use an adapter that breaks the grounding circuit.

This apparatus must be properly grounded for your safety.

9. Protect the power cord from being walked on or pinched, particularly plugs, convenience receptacles, and the point where they exit from

the apparatus.

10.The appliance coupler is the AC mains disconnect and should remain readily operable after installation.

11. Use only attachments/accessories speciﬁed by QSC Audio Products, LLC.

12.Use only with hardware, brackets, and components sold with the apparatus or by QSC Audio Products, LLC.

13.Unplug the apparatus during lightning storms or when unused for long periods of time.

14.Refer all servicing to qualiﬁed service personnel. Servicing is required when the apparatus has been damaged in any way, such as power

supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain

or moisture, does not operate normally or has been dropped.

15.The appliance shall not be exposed to dripping or splashing and no objects ﬁlled with liquids, such as vases, shall be placed on

the apparatus.

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.

QSC Audio Products 3-Year Limited Warranty

QSC Audio Products, LLC (“QSC”) guarantees its products to be free from defective material and / or workmanship for a period of three (3) years from

date of sale, and will replace defective parts and repair malfunctioning products under this warranty when the defect occurs under normal installation

and use - provided the unit is returned to our factory or one of our authorized service stations via prepaid transportation with a copy of proof of

purchase (i.e., sales receipt). This warranty provides that the examination of the return product must indicate, in our judgment, a manufacturing defect.

This warranty does not extend to any product which has been subjected to misuse, neglect, accident, improper installation, or where the date code has

been removed or defaced. QSC shall not be liable for incidental and/or consequential damages. This warranty gives you specific legal rights. This limited

warranty is freely transferable during the term of the warranty period. Customer may have additional rights, which vary from state to state.

In the event that this product was manufactured for export and sale outside of the United States or its territories, then this limited warranty shall not apply.

Removal of the serial number on this product, or purchase of this product from an unauthorized dealer, will void this limited warranty.

Periodically, this warranty is updated. To obtain the most recent version of QSC’s warranty statement, please visit www.qscaudio.com.

QSC is a registered trademark of QSC Audio Products, LLC

“QSC” and the QSC logo are registered with the U.S. Patent and Trademark Ofﬁce

All trademarks are the property of their respective owners.

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" (6.3 mm) TRS, and barrier strip

• Pluggable terminal block and Speakon™ outputs

• 21 detent gain knobs

• Front panel LED indicators for signal and clip and power

• Attenuation control security plate

Stereo mode, both channels driven CMX

300V

CMX

500V

CMX

800V

8Ω/ FTC 20 Hz –20 kHz / 0.1% THD 185 W 260 W 450 W

8Ω /EIA 1 kHz / 0.1% THD 200 W 300 W 500 W

4Ω/ FTC 20 Hz – 20 kHz / 0.1% THD 280 W 400 W 650 W

4Ω/EIA 1 kHz / 0.5% THD 300 W 500 W 800 W

2Ω/EIA 1 kHz / 1% THD 430 W 700 W 1200 W

70V Direct Drive /EIA 1 kHz / 1% THD - - 400 W

Front Panel

1. Power switch

2. Power indicator LED

3. Cooling vents

4. Clip and Signal indicator LEDs, (Channel 1)

5. Attenuation control (Channel 1)

6. Clip and Signal indicator LEDs, (Channel 2)

7. Attenuation control (Channel 2)

8. Lockout plate retention screw

– Figure 1 –

1 2 3 4 56 7

– Table 1 –

Back Panel

1. Barrier strip input

2. XLR inputs, Channels 1 and 2

3. Conﬁguration dip switches

4. TRS inputs, Channels 1 & 2

5. Fan

6. Speakon™ output, Channel 1 and 2

7. Terminal block connector outputs, Channels 1 and 2

8. Circuit Breaker

9. Serial number label

10. Conﬁguration switch chart

11. IEC power inlet (power cord connector)

Features and setup

Clip Limiter

What it is

When the audio signal drives the ampliﬁer's output circuit beyond its power capability, it clips, ﬂattening the peaks of the waveform. The clip limiter

detects this and reduces the gain to minimize the amount of overdrive. To preserve as much of the program dynamics as possible, limiting reduces the

average program level until peaks barely clip.

Each channel has its own clip limiter, and you can switch it on or off independently, as shown in (Figure 3).

When to use it (or not)

When driving full-range speakers, clip limiting reduces high-frequency distortion caused by bass overloads. It also protects higher frequency drivers

from excess overdrive and harsh clipping harmonics.

When driving subwoofers, some users let the ampliﬁer clip without limiting because it gives extra “punch” to kick drums and similar sounds.

CAUTION: In bi-amp systems, excessive limiting will affect the frequency balance.

– Figure 3 –

123 95 6 8 10 114 7

12345679

810 11

– Figure 2 –

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.

When to use it (or not)

As a rule, your speakers will sound better with proper ﬁltering. Unless you already have ﬁltering in a preceding device, match the setting to the low

frequency rating of your speakers. Vented (bass reﬂex, ported, etc.) speakers are especially sensitive to cone over-excursion at frequencies below their

rated limit.

The 50 Hz ﬁlter works well with most compact full-range speakers, and has a slight boost at 100 Hz for greater fullness. The 30 Hz ﬁlter is intended for

subwoofers and large full-range cabinets. The “off” position should be used only for applications such as studio playback monitoring, where you need

to know if there are unwanted sub-audio signals present in your mix.

– Figure 4 –

– Figure 5 –

– Figure 6 –

– Figure 7 –

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.

With the inputs in parallel, you can use the other set of input connectors to carry the signal to other amps (Figure 9). This is often called

a “daisy-chain.”

When to use it

Use the Parallel mode when driving two speakers with one input signal (Parallel mode) while keeping separate control of both channels' gain, ﬁltering,

and limiting. Use Parallel mode and Bridge Mono mode to patch the signal to additional ampliﬁers through the extra input jacks.

Note: If you're using a balanced signal, use only balanced patch cables; even one unbalanced cable will unbalance the entire signal chain, possibly

causing hum.

Note: Turn off the “Parallel Inputs” switches when feeding the amp two separate signals.

– Figure 8 –

– Figure 9 –

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).

When to use it (or not)

Use Bridge Mono mode to deliver the power of both channels to a single 8 or 4Ωload. Set switch positions 6 and 7 to BRIDGE MONO ON

(Figure 10). Use Channel 1's inputs, and connect the speaker as shown in (Figure 12 and 13).

Bridge Mono Precautions

This mode puts a high demand on the ampliﬁer and speaker, Excessive clipping may cause protective muting or speaker damage. Be sure the speaker

has a sufﬁcient power rating.

Output voltages greater than 100 volts RMS are available between the bridged terminals of the CMX 800V. CLASS 3 wiring methods (NEC 1999), as

speciﬁed in accordance with national and local codes, must be used to connect the speaker.

To patch the signal to additional ampliﬁers, use

the parallel input switches described under

Parallel Input Mode.

Channel 2 settings, switches 8, and 10 are

set to off.

– Figure 10 – – Figure 11 –

– Figure 12 – – Figure 13 –

To speaker

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.

• Bi-amped operation, with the low frequencies in Channel 1 and the highs in Channel 2.

Parallel Input Mode

This mode is similar to the Stereo mode, except that the inputs for Channel 1 and Channel 2 are internally connected together. A signal into

Channel 1 jack drives both channels directly (Figure 16). Use Channel 1 Input, do not connect different sources to both channels. Each channel's

attenuation control still functions as usual, and each channel feeds its own speaker load. The dip switches are set as shown in (Figure 17).

In Parallel mode, you can patch the input signal on to additional ampliﬁers by using any of the remaining input jacks. See Ch. 2 in (Figure 16).

Example:

• One mono signal driving both channels, with independent attenuation control for each speaker system.

– Figure 15 –

– Figure 17 –

– Figure 16 –

signal input

NO INPUT!

Can be used to Daisy-chain

additional amplifiers

Amplifier #2

– Figure 14 –

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