The ART Model 311 Precision Stereo 2-Way Active Crossover with Subwoofer Output USER’S GUIDE -1-
TABLE OF CONTENTS Introduction ........................................................................................... 3 Installation ............................................................................................. AC Power Hookup ............................................................................... Analog Audio Connections .................................................................. Safety Precautions .........................................................................
INTRODUCTION Thank you for purchasing an ART 311 - and congratulations: You now own one of the most versatile crossovers available. Offering a superb level of sound quality, the 311 circuit design, combined with a straightforward user interface, quickly and easily gives you access to all of its features. The Model 311 has been carefully designed, engineered and manufactured to provide you with years of great sound and reliable service.
INSTALLATION The 311 may be used in a wide variety of applications and environments. Enclosed in a rack-mountable, all-steel enclosure, the unit is designed for continuous professional use. 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 311 has an internal power supply designed to operate at 115 VAC @ 50 to 60 Hz.
CONTROLS POWER SWITCH The power switch applies and removes power to the Crossover. Make sure all equipment after the 311 is either off or the outputs are turned all the way down before turning on or off the 311. LOW OUTPUT LEVEL CONTROL Each channel of the 311 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. They cover the range of –30dB to +10dB of output gain trim, as indicated on the front panel.
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 311 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. They cover the range of –30dB to +10dB of output gain trim, as indicated on the front panel.
CONNECTIONS It is easy to interface the unit with a wide variety of equipment. The rear panel has balanced XLR and ¼” inputs as well as unbalanced ¼” outputs. XLR INPUT JACKS (REAR) The XLR input connections are balanced and follow the AES standard for wiring: Pin 1 = Ground, Pin 2 = Hot (+), Pin 3 = Cold (-). This input parallels the ¼” inputs. ¼” INPUT JACKS (REAR) The ¼” input connections are balanced with Tip = Hot (+), Ring = Cold (-), and Sleeve = Ground. This input directly parallels the XLR input.
OPERATION The following guideline refers to a P.A. system, but the same basic ideas apply to a home recording setup or a Hi-Fi system. A stereo 2-way sound system is typically set up as follows: Separate high frequency (horn or tweeter) and low frequency (bass) cabinets are used for each side (left and right) of the sound system. The crossover is used to split each side of the stereo signal into two frequency bands, which will feed separate power amplifiers.
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.
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, (A R T) 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 one year from the date of purchase.
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 the unit has the proper power supplied, all cables are connected correctly, and the cables themselves are in working condition. 2) If you find the unit to be at fault, write down a complete description of the problem, including how and when the problem occurs.
311 SPECIFICATIONS Dimensions Weight Input Connections Output Connections Input Impedance Output Impedance Maximum Input Level Maximum Output Level CMRR Frequency Response Signal to Noise Ratio 1.75”H x 19”W x 5.5”D 4.85 lbs. (2.2 kg) XLR, ¼” TRS, balanced ¼”TS, unbalanced 100K ohms 220 ohms +21dBu +21dBu >75dB (typical @ 1kHz) 10Hz to 40kHz, +/-.5dB >95dB, Ref: 0dBu 20Hz to 20kHz, unweighted Dynamic Range >114dB Total Harmonic Distortion <0.
