QSC Audio CMX 500V, CMX 800V, CMX 300V User Manual

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. 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 6-Year Limited Warranty

QSC Audio Products, LLC (“QSC”) guarantees its products to be free from defective material and / or workmanship for a period of six (6) 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. Contact us at 800-854-4079 or visit our web site at www.qscaudio.com.

© Copyright 2010, QSC Audio Products, LLC 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

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)

CMX 300V

– Table 1 –

5. Attenuation control (Channel 1)

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

7. Attenuation control (Channel 2)

8. Lockout plate retention screw

CMX 500V

CMX

800V

1 2 3 4

– Figure 1 –

6 7

Back Panel

3 95 6 8 10

114 7

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)

10 11

– Figure 2 –

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 –

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 –

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