User Guide SCM810/SCM810AZ EIGHT-CHANNEL MICROPHONE MIXER ©2006, Shure Incorporated 27A8868 (Rev. 1) Printed in U.S.A.
TABLE OF CONTENTS DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 SYSTEM FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 OPERATING PRINCIPLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 FRONT PANEL FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DESCRIPTION The Shure Model SCM810/E is an eight-channel automatic microphone mixer designed for use in sound reinforcement, audio recording, and broadcast applications. The SCM810 dramatically improves audio quality in any application where multiple microphones are required. Any low-impedance dynamic or condenser microphone (including wireless) can be used with the SCM810/E. Multiple SCM810 mixers can be linked to other SCM810/E mixers, as well as to Shure Models FP410, SCM410, SCM800, and AMS8100 mixers.
FRONT PANEL FEATURES 쐅 MODEL SCM810 FRONT PANEL FIGURE 1 Microphone Channel Gain Controls 1–8: Allows adjustment of Aux INPUT 1/4-inch Phone Jack: Mixes external auxiliary- or microphone gain. Input LED 1–8: Lights green when channel is active; lights red at 6 dB below clipping level. Low-Cut Filter 1–8: Recessed screwdriver adjustment provides adjustable low-frequency rolloff (high pass) to reduce undesirable low-frequency signals.
DIP SWITCHES The rear-panel DIP switch provides the following setup options. The positions shown in bold type are the factory settings. (MIXER REAR PANEL) NOTE: Switch positions and effects are shown in Figure 3 and also on the mixer label.
INSTALLATION AND SYSTEM SETUP RACK MOUNTING THE MIXER To mount the SCM810 in a standard 483 mm (19-inch) audio equipment rack, slide the mixer into the rack and secure it with the supplied Phillips head screws, as shown in Figure 4. Use all four screws. RACK MOUNTING THE SCM810/E FIGURE 4 SCM810/E CONNECTIONS Make audio connections as follows (see Figure 5). 1. Connect microphone- or line-level signal sources to the Channel Input connectors (use conventional 2-conductor shielded cables). 2.
EQUALIZER FUNCTIONS Low Cut Filter (High-Pass) The low-cut (or high-pass) filter allows all frequencies above its cutoff point to pass from filter input to filter output without attenuation, while frequencies below the cutoff are attenuated (see Figure 6). The cutoff point is defined as the frequency where the signal has dropped 3 dB relative to the flat, or bandpass, region. Below the cutoff point, the filter exhibits increasingly more attenuation as the frequency diminishes.
NETWORKING MULTIPLE MIXERS If additional inputs are needed, more SCM810 mixers (as many as 50) can be “linked” using supplied link cables. Such a configuration can provide up to 400 microphone inputs. As long as the link jacks of all mixers are connected (out-to-in, sequentially, leaving one Link In and one Link Out jack unconnected), the automatic mixing functions will be shared by all units. All input signals appear at all linked mixer outputs. There is no master/slave relationship.
SPECIFICATIONS Measurement Conditions (unless otherwise specified): Line voltage 120 Vac, 60 Hz (SCM810) or 230 Vac, 50 Hz (SCM810E); full gain; 1 kHz, one channel activated; source impedances: Mic 150 Ω, Line 150 Ω; terminations: Line 10 kΩ, Phones 300 Ω (tip-sleeve and ring-sleeve), Direct Out 10 kΩ; Auto mode, equalization controls adjusted for flat response Frequency Response (Ref 1 kHz, channel controls centered) 50 Hz to 20 kHz ±2 dB; -3 dB corner at 25 Hz Voltage Gain (typical, controls full clockwis
ADVANCED FUNCTIONS The SCM810's Advanced Functions are recommended only for those who are technically knowledgeable and familiar with audio electronics. LOGIC CONNECTION SPECIFICATIONS The logic functions of the SCM810 expand the mixer's range of installation and control options. Logic can be used for everything from simple cough switches to elaborate computer-controlled room systems. (Shure's AMS Update publication contains additional applications of advanced logic.
SUGGESTED LOGIC APPLICATIONS Remote Channel-On Indicators This section contains suggestions on the uses of the SCM810's logic capabilities. Note that uses of these functions are not limited to the listed applications. The user is limited only by individual imagination and creativity. For additional suggestions and solutions to installation problems, contact Shure's Applications Group. Remote indicators can be used to indicate when a talker's microphone is on.
Inhibiting Gating for Unwanted Sounds As described in the Operating Principles section, MaxBus attempts to activate only one microphone per sound source. Muting a microphone channel prevents its audio from appearing at the mixer's output. However, the muted microphone still communicates with other mic channels via MaxBus. A sound source picked up by a muted microphone will not activate other microphones.
Diode Isolation of Logic Controls Mixer logic may be used with 15-volt CMOS logic if a pull-up resistor is used with each GATE output (see Figure 20-Channel 1 modified). Two or more control functions using the same logic pins can be isolated with diodes. In this manner a channel can be muted by an overall group mute switch, or by its own cough button (see Figure 19-Channels 1, 3 and 5 modified). + 15 V POWER SUPPLY 5.
INTERNAL MODIFICATIONS WARNING: All modifications must be performed by qualified service technicians. 3. For individual channel modifications, the first number of the reference designation refers to its channel number, i.e., R1027 refers to a Channel 1 resistor, X7216 refers to a Channel 7 jumper, etc. All references to Channels 1 through 8 in the following paragraphs use Channel 1 jumpers and resistors as reference. Modifications affecting the Master section are preceded by the number “9" (X901, etc.).
SCM810 Speech Gate for Mixing Console The SCM810 can be used in conjunction with large mixing consoles to provide automatic mixing for talk shows, panel discussions, and news shows. Large consoles have channel insert jacks so that external signal processing devices can be patched into individual channel signal paths. With this modification the SCM810 can be placed into unbalanced insert jacks, and the SCM810 used as a high-quality, external, 8-channel speech gate.
Increase Hold Time In addition to the dip switch SW702 options of 0.4- and 1.0-second hold time, the hold time can be increased to 1.5 seconds. (More than 1.5 seconds is not recommended.) Procedure: Install a 470 kΩ resistor across jumper points X902. Move DIP switch down to 1.0-second position. Decrease Hold Time The hold time can be decreased from the factory preset of 0.4 seconds to 0.3 seconds. (Less than 0.3 seconds is not recommended.) Procedure: Install a 2 MΩ resistor at jumpers X903.
SHURE Incorporated http://www.shure.com SHURE Incorporated http://www.shure.com United States, Canada, Latin America, Caribbean: 5800 W. Touhy Avenue, Niles, IL 60714-4608, U.S.A. Phone: 847-600-2000 U.S. Fax: 847-600-1212 Intl Fax: 847-600-6446 Europe, Middle East, Africa: Shure Europe GmbH, Phone: 49-7131-72140 Fax: 49-7131-721414 Asia, Pacific: Shure Asia Limited, Phone: 852-2893-4290 Fax: 852-2893-4055 美国、加拿大、拉丁美洲、加勒比海地区： 5800 W. Touhy Avenue, Niles, IL 60714-4608, U.S.A.
