Art CX311 User manual

CX311
Stereo 2-Way Active Crossover with Subwoofer Output
USER'S GUIDE

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IMPORTANT SAFETY INSTRUCTIONS – READ FIRST
This symbol, wherever it appears, This symbol, wherever it appears, alerts you
alerts you to the presence of uninsulated to important operating and maintenance
dangerous voltages inside the enclosure that instructions in the accompanying literature.
may be sufficient to constitute a risk of shock. Please read the manual.
Read instructions
Retain these safety and operating instructions for future reference. Heed all warnings printed here and on the
equipment. Follow the operating instructions printed in this user guide.
Do not open
There are no user serviceable parts inside. Refer any service work to qualified technical personnel only.
Power sources
Only connect the unit to mains power of the type described in this user guide or marked on the rear panel. The
power source must provide a good ground connection.
Power cord
Use the power cord with sealed mains plug appropriate for your local main supply as provided with the
equipment. If the provided plug does not fit into you outlet consult your service agent. Route the power cord so
that it is not likely to be walked on, stretched or pinched by items placed upon or against.
Grounding
Do not defeat the grounding and polarization means of the power cord plug. Do not remove or tamper with the
ground connection on the power cord.
Moisture
To reduce the risk of fire or electrical shock, do not expose the unit to rain, moisture or use in damp or wet
conditions. Do not place container of liquid on it, which may spill into any openings
Heat
Do not locate the unit in a place close to excessive heat or direct sunlight, as this could be a fire hazard.
Locate the unit away from any equipment, which produces heat such as: power supplies, power amplifiers and
heaters.
Environment
Protect from excessive dirt, dust, heat, and vibration when operating and storing. Avoid tobacco ash, drink
spillage and smoke especially that associated with smoke machines.
Handling
Protect the controls from damage during transit. Use adequate padding if you need to ship the unit. To avoid
injury to yourself or damage to the equipment take care when lifting, moving or carrying the unit.
Servicing
Switch off the equipment and unplug the power cord immediately if it is exposed to moisture, spilled liquid or
the power cord or plug becomes damaged during a lightning storm or if smoke odor or noise is noted. Refer
servicing to qualified technical personnel only.
Installation
Install the unit in accordance with the instruction printed in the user guide.

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IMPORTANT SAFETY INSTRUCTIONS – READ FIRST.......................................................... 2
OVERVIEW..................................................................................................................................................4
Features.........................................................................................................................................................4
INSTALLATION .........................................................................................................................................5
AC Power Hookup..........................................................................................................................................5
Input/Output Connections...............................................................................................................................5
OPERATION ..................................................................................................................................................6
FRONT PANEL CONTROLS ................................................................................................................6
Power Switch..............................................................................................................................................6
Low Output Level Controls .........................................................................................................................6
Low Cut Filter Switch..................................................................................................................................6
Crossover Frequency Control.....................................................................................................................6
High Output Level Control ..........................................................................................................................6
Phase Switch..............................................................................................................................................6
Sub Output Level Control ...........................................................................................................................7
Subwoofer Frequency Control ....................................................................................................................7
REAR PANEL CONNECTORS............................................................................................................. 7
XLR Input Jacks .........................................................................................................................................7
1/4” Input Jacks ..........................................................................................................................................7
1/4” Output Jacks .......................................................................................................................................7
APPLICATIONS.........................................................................................................................................8
Typical Setup .................................................................................................................................................8
Signal Flow ....................................................................................................................................................8
Initial Setup Tips ............................................................................................................................................8
WARRANTY INFORMATION...............................................................................................................9
Limited Warranty............................................................................................................................................9
Exclusions......................................................................................................................................................9
SERVICE ....................................................................................................................................................10
SPECIFICATIONS ..................................................................................................................................11

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OVERVIEW
The ART CX311 Stereo 2-Way Active Crossover with Subwoofer Output offers a superb level of
sound quality and its straightforward user interface gives you quick and easy access to all of its
features. Designed for home, club, or DJ system applications or live sound reinforcement, the CX311
employs 24dB/ octave state-variable, fourth-order, Linkwitz-Riley filters. These filters guarantee in-
phase outputs at all frequencies. This ensures the proper acoustic summing of common signals from
adjacent drivers in the crossover region.
The CX311 is a stereo 2-way electronic crossover with an additional subwoofer output. Each
crossover channel splits the frequency of an input signal into two separate signals, which may then
be sent to amplifiers or other signal processing equipment in a sound system. The subwoofer output
can be used to add punch to low bass audio.
Each stereo channel features high and low output level and crossover frequency rotary controls, while
the subwoofer channel features its own output level and crossover frequency rotary controls. A low
cut switch for each channel may be used to remove unwanted subsonic audio that can damage
amplifiers or speakers. Each stereo channel also includes a phase switch that can be used to detect
or correct audio path connection errors. The rear panel features balanced XLR and 1/4” TRS input
and output connectors. Power for the CX311 is internal.
The ART CX311 Stereo 2-Way Active Crossover with Subwoofer Output has been carefully designed,
engineered and manufactured to provide you with years of great sound and reliable service.
Features
•Stereo 2-way operation with separate subwoofer output
•Fourth-order Linkwitz-Riley filters
•Balanced XLR and 1/4” TRS inputs and unbalanced 1/4” outputs
•Adjustable, wide crossover frequency range (250Hz to 6kHz)
•Independent output level control for each output
•Switchable low cut (30Hz) filters on each stereo channel and subwoofer
•Phase reverse switch on each stereo channel's High output
•Rugged, fully shielded all-steel chassis
•Internal AC power supply with standard IEC connector
•Three year warranty

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INSTALLATION
The ART CX311 may be used in a wide variety of applications and environments. Enclosed in a 1U
(1.75 inches high) rack-mountable, all-steel enclosure, the unit is designed for continuous
professional use. The depth is 5 inches. Mounting location is not critical. However, for greater
reliability, we recommend that you not place the unit on top of power amps or other sources of heat.
AC POWER HOOKUP
The CX311 has an internal power supply designed to operate from 105 to 120VAC at 50/60Hz. Units
manufactured for use outside of the United States have been modified to comply with the required
electrical specifications for the country of destination. Before plugging the CX311 into the AC mains,
make sure that all of the equipment following the crossover outputs are turned off or that all of the
outputs are turned down.
INPUT/OUTPUT CONNECTIONS
The CX311 has XLR and 1/4" TRS phone jack connectors for each input. Audio input connections are
active balanced although the 1/4" phone jack connections can easily be converted to unbalanced
operation by using two-conductor phone plugs. All output connections are unbalanced and use 1/4”
TS phone jacks.

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OPERATION
FRONT PANEL CONTROLS
POWER SWITCH
The POWER switch applies and removes power to the unit. Make sure that all equipment after the
CX311 is either off or the outputs are turned all the way down before turning the CX311 on or off.
LOW OUTPUT LEVEL CONTROLS
Each channel of the CX311 has a LOW OUTPUT LEVEL control. These controls are used to trim the
output levels to the LOW OUTPUT jacks on the rear of the unit.
These controls cover the range of –30dB to +10dB of output gain trim, as indicated on the front panel.
In most cases you would set them to 0dB, for flattest response from the crossover. You can use these
controls to compensate for amplifier gain variations or efficiency of your speakers.
LOW CUT FILTER SWITCH
The LOW CUT switch activates a 30Hz high pass filter. There is one for each of the LOW OUTPUT
jacks and one for the SUBWOOFER OUTPUT. This filter is a 2-pole Butterworth design
(12dB/octave). Its response reduces spurious subsonic frequencies, which tightens up the low end
and helps to protect your amplifiers and speakers.
CROSSOVER FREQUENCY CONTROL
Each channel of the CX311 has a crossover FREQUENCY control to set the crossover point for the
high and low frequencies. These controls cover the frequency range of 250 Hz to 6 kHz. All
frequencies below the set frequency will be sent to the LOW OUTPUT and all frequencies above the
set frequency will be sent to the HIGH OUTPUT.
The main crossover filters are 4-pole Linkwitz-Riley designs (24dB/octave). This yields a sharp rolloff
to help protect speakers and the outputs sum to a flat response.
HIGH OUTPUT LEVEL CONTROL
Each channel of the CX311 has a HIGH OUTPUT LEVEL control. These controls are used to trim the
output levels to the HIGH OUTPUT jacks on the rear of the unit.
These controls cover the range of –30dB to +10dB of output gain trim, as indicated on the front panel.
In most cases you would set them to 0dB, for flattest response from the crossover. You can use these
controls to compensate for amplifier gain variations or efficiency of your speakers.
PHASE SWITCH
Each channel of the CX311 has a PHASE switch. These switches are used to switch the polarity
(invert the phase) of the signals going to the HIGH OUTPUT jacks. Normally you would leave these

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switches in the out (NORM) position. Pushing a button in (INVERT position) may be used to help
correct audible phase-related problems.
SUB OUTPUT LEVEL CONTROL
This control is used to trim the audio output level to the SUBWOOFER OUTPUT jack on the rear of
the unit. The subwoofer signal is used to provide extra bass via a mono subwoofer speaker in your
system.
This control covers the range of –30dB to +10dB of output gain trim, as indicated on the front panel.
In most cases you would set it to 0dB. You can use this control to compensate for amplifier gain
variations or efficiency of your speaker.
SUBWOOFER FREQUENCY CONTROL
The SUBWOOFER FREQUENCY control sets the crossover point for signals going to the
SUBWOOFER OUTPUT jack. This control covers the frequency range of 50 Hz to 250 Hz. For this
function, both of the input channel signals are combined and frequencies below the set frequency will
be sent to the SUBWOOFER OUTPUT. This is in addition to the normal signals that are sent to each
of the channels other outputs.
REAR PANEL CONNECTORS
It is easy to interface the unit with a wide variety of equipment. The rear panel has balanced XLR and
1/4” inputs as well as unbalanced 1/4” outputs.
XLR INPUT JACKS
The XLR input connections are balanced and follow the AES standard for wiring: Pin 1 = Ground, Pin
2 = Hot (+) and Pin 3 = Cold (-). These inputs directly parallel the 1/4” inputs.
1/4” INPUT JACKS
The 1/4” input connections are balanced with Tip = Hot (+), Ring = Cold (-), and Sleeve = Ground.
These inputs directly parallel the XLR inputs.
1/4” OUTPUT JACKS
The 1/4” output jacks are unbalanced with Tip = Hot (+) and Sleeve = Ground. They are used for
sending signals to amplifiers, or other unbalanced equipment.

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APPLICATIONS
Typical Setup
For a stereo 2-way system, separate high frequency (horn or tweeter) and low frequency (bass)
speaker cabinets are used for each channel (left and right) of the sound system and are driven by
their own power amplifiers.
The crossover is used to split each channel's signal into two frequency bands, which feed separate
amplifiers. This delivers the proper frequencies to each speaker cabinet as well as allowing its
associated amplifier to produce acoustic power more efficiently.
It is very important that you use caution when selecting the crossover points for any system.
Refer to the documentation that came with your speaker cabinets for information on their
proper frequency ranges. This is especially important for high frequency horns; damage may
occur from sending lower frequencies than specified into the drivers!
Signal Flow
In most situations, the crossover is the last piece of equipment in the signal chain before the power
amplifiers. Signal flow is as follows:
Mixer → Equalizer → Crossover →Power Amplifier →Speaker Cabinets
Sometimes a limiter is placed between the mixer outputs and the equalizer or after the equalizer for
system protection.
Initial Setup Tips
1. Set all level controls to their full counter-clockwise position (-30dB.)
2. Connect the outputs of your mixer (or equalizer) to the inputs of the CX311. If stereo,
Channel One is left.
3. Connect the LOW output of Channel One to the power amplifier powering the low frequency
cabinets (left).
4. Connect the HIGH output of Channel One to the power amplifier powering the high frequency
cabinets (left).
5. Repeat for the right side of the system (Channel Two).
6. Connect the SUBWOOFER output to the subwoofer amplifier.
7. Set the crossover frequency for both channels (they should be the same if your PA cabinets
are the same).
8. Set the crossover frequency for the SUBWOOFER output to that recommended for the
subwoofer.
9. With the power amplifier volume controls turned all the way down, turn on all equipment in
the system.
10. With a program source running through the system, turn up the power amplifier volume
controls and slowly turn up the crossover output controls while checking each individual
output for sound and performance.

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WARRANTY INFORMATION
Limited Warranty
Applied Research and Technology will provide warranty and service for this unit in accordance with
the following warrants:
Applied Research and Technology, (ART) warrants to the original purchaser that this product and the
components thereof will be free from defects in workmanship and materials for a period of three
years from the date of purchase. Applied Research and Technology will, without charge, repair or
replace, at its option, defective product or component parts upon prepaid delivery to the factory
service department or authorized service center, accompanied by proof of purchase date in the form
of a valid sales receipt.
Exclusions
This warranty does not apply in the event of misuse or abuse of the product or as a result of
unauthorized alterations or repairs. This warranty is void if the serial number is altered,
defaced, or removed.
ART reserves the right to make changes in design or make additions to or improvements upon this
product without any obligation to install the same on products previously manufactured.
ART shall not be liable for any consequential damages, including without limitation damages resulting
from loss of use. Some states do not allow limitations of incidental or consequential damages, so the
above limitation or exclusion may not apply to you. This warranty gives you specific rights and you
may have other rights, which vary, from state to state.
For units purchased outside the United States, an authorized distributor of Applied Research and
Technology will provide service.

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SERVICE
The following information is provided in the unlikely event that your unit requires service.
1. Be sure that the unit is the cause of the problem. Check to make sure that the unit has power
supplied, that all cables are connected correctly, and that the cables themselves are in working
condition. You may want to consult with your dealer for assistance in troubleshooting or testing
your particular configuration.
2. If you believe that the ART unit is at fault, go to www.artproaudio.com. You may contact Customer
Service for more assistance, or directly request a Return Authorization for service in the
“resources” area of the website.
3. If you are returning the unit for service, pack the unit in its original carton or a reasonable
substitute. The original packaging may not be suitable as a shipping carton, so consider putting
the packaged unit in another box for shipping. Print the RA number clearly on the outside of the
shipping box. Print your return shipping address on the outside of the box.
4. Include with your unit: a note with the RA number and your contact information, including a return
shipping address (we cannot ship to a P.O. box) and a daytime phone number, and a description
of the problem, preferably attached to the top of the unit. Also include a copy of your purchase
receipt.
Fill in the following information for your reference:
Date of purchase ___________________
Purchased from ___________________
Serial Number ___________________