User manual DOD SIGNAL PROCESSORS

[. . . ] Signal Processors 18-0121-B 6/8/99 10:24 AM Page 1 C ONTENTS RTA SERIES II. . . . . . . . . . . . . . . . . . . . . 2 8 3 4 / 8 3 5 S E R I E S I I. . 20 1 Signal Processors 18-0121-B 6/8/99 10:24 AM Page 2 2 CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN A T T E N T I O N : RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR W A R N I N G : TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE The symbols shown at left are internationally accepted symbols that warn of potential hazards with electrical products. The lightning flash with arrowpoint in an equilateral triangle means that there are dangerous voltages present within the unit. The exclamation point in an equilateral triangle indicates that it is necessary for the user to refer to the owner's manual. [. . . ] The gain control can be used to boost the signal if needed. 834: Apply power to the mid frequency amplifier and turn up the MID level control to the desired level. 834/835: Finally, apply power to the high frequency power amplifier and bring up the HIGH level control to the desired level. Once the output levels are set, any phase problems can be corrected with the phase inversion switches on the rear panel (834 only). THE PHASE INVERSION SWITCHES ON THE 834 ARE MECHANICAL SWITCHES AND SHOULD ONLY BE CHANGED WHEN THE POWER AMPLIFIER FOR THAT OUTPUT IS OFF. Turning down the level controls on the 834 will not prevent transients from appearing at the outputs when changing the phase switches while the crossover is on. These transients can damage power amplifiers, speakers, Signal Processors 18-0121-B 6/8/99 10:25 AM Page 15 and drivers. STEREO OPERATION USING A MONO SUBWOOFER This mode of operation provides: 834: Channel 1 and Channel 2 high frequency outputs, Channel 1 and Channel 2 mid frequency outputs, and one summed low frequency output. 835: Channels 1 and 2 high frequency outputs and one summed low frequency output. 15 The setup procedure is the same as for the stereo mode, except that, instead of connecting both low frequency outputs, connect only the Low Frequency Sum output to the low frequency amplifier. Set both LOW level controls to the same level to ensure that both controls contribute the same amount of signal to the Low Frequency Sum output. Note: that there is no phase inversion switch on the 834 for the Low Frequency Sum output. Any phase problems must be corrected using the phase inversion switches on the other four outputs. MONO OPERATION Depress the Stereo/Mono switch (LED indicator lit). When operating the crossover in stereo mode, the MID/HIGH frequency control of the 834 is variable from . 75 kHz - 7. 5 kHz. When operating the crossover in mono mode, the HIGH-MID/HIGH frequency control range is from 2 kHz - 20 kHz. The mono mode setup procedure is the same as for stereo mode, except that the bottom row of markings on the front and rear panels will be followed instead of the top row. Be sure that the amplifiers are off, that the gain control is set to 0 dB, and that the level control is set to - before proceeding to adjust the crossover frequencies and levels. The Low Frequency Sum output is not usable in the mono mode. 834 SPECIFICATIONS Crossover type: Stereo 3-way, Mono 4-way. I/O Connectors: 834: 1/4" tip-ring-sleeve phone jacks for balanced/unbalanced connections. 834 XLR: Inputs: balanced female XLR, Outputs: balanced male XLR. Signal-To-Noise Ratio: Greater than -90 dB Filter Type: 18 dB/octave Butterworth state-variable filters. Signal Processors 18-0121-B 6/8/99 10:25 AM Page 16 16 835 Crossover Frequencies - Stereo: LOW/MID: 50 Hz to 5 kHz in two ranges, MID/HIGH: 750 Hz to 7. 5 kHz. - Mono: LOW/LOW-MID: 50 Hz to 5 kHz in two ranges, LOW-MID/HIGH-MID: 50 Hz to 5 kHz in two ranges, HIGH-MID/HIGH: 2 kHz to 20 kHz. Input Impedance: 20 k unbalanced, 40 K balanced. Maximum Input Level: +21 dBu (ref. : 0. 775 Vrms). Maximum Output Level: +21 dBu (ref. : 0. 775 Vrms). SPECIFICATIONS Crossover type: Stereo 2-way, Mono 3-way. I/O Connectors: 835: Inputs: 1/4" tip-ring-sleeve phone jacks for balanced/unbalanced connections. [. . . ] This is done by inserting the control signal into the Side Chain Input. Ducking is a good example of this type of application. Ducking is simply gain reduction of a signal when another is present. This technique is widely used in sports broadcasting to reduce the level of the crowd background signal when the announcer is speaking. [. . . ]