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. . . . . . . . . . . . . . . .. . 11 8 4 4 S E R I E S I I . . . . . . . . . . . . . . . . . . . .. . 17 8 6 6 S E R I E S I I . . . . . . . . . . . . . . . . . . . . . .
Signal Processors 18-0121-B 2 6/8/99 10:24 AM Page 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.
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 3 3 These units comply with the European “EMC Directive” for emissions and susceptability The power cord is terminated in a CEE7/7 plug (Continental Europe). The green/yellow wire is connected directly to the unit's chassis. If you need to change the plug, and if you are qualified to do so, refer to the table below.
Signal Processors 18-0121-B 4 6/8/99 10:24 AM Page 4 RTA SERIES II 20 25 31.5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 1K 1.25K 1.6K 2K 2.5K 3.15K 4K 5K 6.3K 8K 10K 12.5K 16K 20K 2/6 WINDOW RES.
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 5 5 The DOD RTA Series II also has its own internal pink noise generator and level control. Pink noise is defined as an audio signal that contains all frequencies at equal energy levels. For this reason, pink noise sounds a lot like static. Pink noise is useful when setting up P.A. systems and audio systems when you need to see the frequency response of the system.
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 6 6 REAR PANEL CONTROLS Auxiliary Microphone Input Jack: A female XLR-type connector intended for use with microphones other than the calibrated microphone provided with the RTA. This jack accepts low impedance microphones. Line Input Jack: This is a 1/4-inch phone jack that may be connected to unbalanced line level sources. Line Output/Pink Noise Output Jack: A 1/4-inch phone jack that provides connection to unbalanced line level inputs.
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 7 7 characteristics vary greatly as you move around the room (particularly with multiple driver systems). If you find that different areas of the room behave differently, try to average the settings on the equalizer to correct the room as a whole. You don’t need to blast the system with pink noise. Use just enough level from the RTA to overcome any ambient room noise (such as air conditioners or traffic noise).
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 8 8 several positions in the room and compromise the equalization/attenuation setting for the best possible sound. This may be done either with the equalizer or by aiming the tweeters of the main speakers differently. Low frequency dips and peaks are room-related, and may be corrected to some extent.
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 9 9 Another method for equalizing a monitor system uses the stage microphones without the RTA’s calibrated microphone. Most reinforcement type microphones are not flat in their frequency response. This procedure, however, takes the stage microphone’s response into account as you equalize the system. Use the system’s own microphones to sample the sound field on stage using the pink noise generator signal.
Signal Processors 18-0121-B 6/8/99 10:24 AM 10 Page 10 SPECIFICATIONS Number of Frequency Bands: 31. Display Range: 1 dB step per LED, or 3 dB step per LED. Level Range: 53 dB to 107 dB SPL. Display Attack Time: Peak, Instantaneous. Frequency Accuracy: ±4%. Pink Noise: Pseudo-random, digital synthesized. Pink Noise Level: -26 dBu to -7 dBu. Calibrated Microphone: Omni-directional, back-electret condenser-type, RTA powered. Microphone Sensitivity: -64 dB, ±3 dB (0dB =1V/µbar @ 1kHz).
Signal Processors 18-0121-B SERIES 834/835 LOW LEVEL MID LEVEL HIGH LEVEL 125 HIGH PASS 834seriesII stereo crossover 40 Hz HIGH PASS 375 0 dB GAIN +15 -∞ 0 dB -∞ dB 0 -∞ 50 0 dB Hz .75 LOW LEVEL 11 LOW LEVEL x10 40 Hz MID LEVEL 375 0 dB +15 -∞ 0 dB -∞ LOW-MID RANGE LOW / HIGH FREQUENCY 500 HIGH LEVEL 0 dB 50 -∞ dB HIGH-MID HIGH 0 835seriesII MONO LOW LEVEL dB +15 GAIN -∞ dB 0 LOW LEVEL -∞ STEREO 5.6 15 .75 2 kHz 7.
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 12 12 power amplifiers to be much smaller, yet adequate to handle the demands of the high frequency content of the program material. Since each element of the system is driven by its own amplifier, any distortion that occurs is limited to the frequencies of the overdriving power amplifier. The rest of the signal remains clear and undistorted.
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 13 13 FOR UNBALANCED AMPLIFIER CONNECTION: To make an unbalanced connection to the unit's XLR connectors, wire the line connectors as follows: Pin 2: high Pin 3: NO CONNECTION Pin 1: ground Use tip-sleeve 1/4" phone plug connectors for connection to the amplifiers, wired as follows: tip: high sleeve: ground Note: The 834 1/4" jacks may be connected balanced or unbalanced and that the 835 has both balanced and unbalanced outputs.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 14 14 • 834: Set the LOW/MID crossover frequency for each channel according to the front panel markings. 835: Set the LOW/HIGH crossover frequency for each channel according to the front panel markings. • 834: If the desired frequency is above 500 Hz, the Range switch must be engaged (LED indicator lit). If the desired frequency is below 500 Hz, the Range switch must be disengaged (LED indicator off).
Signal Processors 18-0121-B and drivers. 6/8/99 10:25 AM Page 15 15 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.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 16 16 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 Ω unbalanced, 40 K Ω balanced. Maximum Input Level: +21 dBu (ref.: 0.775 Vrms). Output Impedance: 102 Ω.. Maximum Output Level: +21 dBu (ref.: 0.775 Vrms).
Signal Processors 18-0121-B S ERIES 844 -25 10:25 AM II CHANNEL ONE 844seriesII 6/8/99 CHANNEL TWO 1 45 -25 45 -25 KEY GATE KEY GATE KEY OUT EXT. OUT EXT. OUT EXT. IN INT. IN INT. IN INT. dBu +10 0.02 THRESHOLD sec 5 0 dB 90 RELEASE ATTENUATION quad noise gate INTRODUCTION -60 dBu +10 0.02 THRESHOLD 17 CHANNEL THREE 1 GATE -60 Page 17 sec REL 5 0 dB 90 ATTENUATION -60 dBu CHANNEL FOUR 1 +10 0.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 18 18 APPLICATIONS The 844 Series II Quad Noise Gate can be used in a variety of situations. The most typical use is a standard noise gate. With the Key Source switch set to INT and the Attenuation control set to 90 dB, the unit will attenuate the input signal when its level falls below the threshold level. The release control (fade time) can be set to begin the attenuation very slowly or very quickly as desired.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 19 19 • Switch the Key Source control to Ext. The detector will now ignore the high frequency signals (in this case, the cymbals), and will allow the drum signal though only when the drum is struck. Keying can be used for more than simply removing noise. If a drum machine is connected to the Key input, the signal at the channel input will be synchronized with the drum machine signal.
Signal Processors 18-0121-B 6/8/99 10:25 AM 20 Page 20 SERIES II GATED COMPRESSOR/LIMITER 866 CHANNEL ONE +6 -30 OPEN 866seriesII gated compressor/limiter dBu -10 GATE THRESHOLD 0 dB INPUT GAIN -10 +12 -40 dBu 4:1 ∞:1 +20 1:1 COMPRESSOR THRESHOLD CHANNEL TWO 1dB 0.25 10 0 1dB +6 -30 3dB -10 4:1 0.1 msec 100 0.05 ATTACK sec 2.5 -18 RELEASE 0 3dB 5dB COMPRESS STEREO LINK 10dB 15dB RATIO 0.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 21 21 will light whenever the signal is being gated. To disable the gating action, set the Gate Threshold control to the full counter-clockwise position (the gate control is fully independent of all other controls on the 866). Input Gain: The Input Gain control allows you to adjust the signal level to the compressor.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 22 22 Stereo Link: Depressing the Stereo Link switch links the two compressor channels for stereo operation. In stereo mode, the compressor will react to either channel, while reducing gain in both channels. Both channels of the 866 are identical in control and function EXCEPT when placed in the stereo mode.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 23 23 The Compressor Threshold controls the point above which the compressor begins to reduce the gain. For compression, the Compressor Threshold is set low, so that even low level signal will activate the compression. For limiting, the Compressor Threshold is set high so that all of the dynamics of the signal are preserved, but extremely high levels are reduced to protect amplifiers, speakers, or to prevent tape saturation.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 24 24 application in which the compressor is to be used. Hiss and signal processor idling noise are common sound reinforcement problems. The more signal processors there are in line with the program material, the more noise is produced at the final output stage. For this reason DOD has incorporated a noise gate in the 866. A gate acts like a compressor in reverse. When a signal crosses the gate threshold, it is allowed to pass unaffected.
Signal Processors 18-0121-B 6/8/99 STEREO OPERATION 10:25 AM Page 25 25 Compressing a two-channel (stereo) signal with two independent compressors creates a problems: if one channel is compressed more than the other, the stereo image will shift to one side, causing an imbalance in the perceived stereo sound field. To prevent shifting, DOD has incorporated a Stereo Link switch on the 866.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 26 26 in that frequency range, thus reducing the sibilance of the program material. Attack and Release times should be set fairly short, and the compression ratio should be below 8:1. SPECIFICATIONS Frequency Response: 10 Hz - 30 kHz, ±0.5 dB. THD+Noise: 0.06%. Signal-To-Noise Ratio: -97 dB. Input Impedance: 20 KΩ unbalanced, 40kΩ balanced. Maximum Input Level: +21 dBu (ref.:0.775 Vrms). Output Impedance: 51Ω unbalanced, 102Ω balanced.
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 27 O WNER'S M ANUAL SIGNAL PROCESSORS D O D E L E C T R O N I C S C O R P O R AT I O N A Harman International Company
Signal Processors 18-0121-B 6/8/99 10:25 AM Page 28 DOD E LECTRONICS C ORPORATION 8760 S OUTH S ANDY PARKWAY S ANDY, U TAH 84070 I NTERNATIONAL D ISTRIBUTION 3 O VERLOOK D R . U NIT 4 A MHERST, N EW H AMPSHIRE 03031 U.S.A FAX (603) 672-4246 DOD IS A R EGISTERED T RADEMARK DOD E LECTRONICS © 1994 DOD E LECTRONICS C ORPORATION P RINTED I N U.S.A. 2/94 M ANUFACTURED I N T HE U.S.A.
