CLOCKAUDIO MR88 Automatic Microphone Mixer Version 4.2 Clockaudio Limited,22 Arnside Road WATERLOOVILLE Hampshire. UK Tel : +44 (0)2392 251193 Fax : +44 (0)2392 251201 Email : sales@clockaudio.co.
CONTENTS INTRODUCTION ............................................................................................................ 3 Features............................................................................................................................. 4 MR88 Front Panel ............................................................................................................ 5 MR88 Rear Panel ...................................................................................................
INTRODUCTION The MR88 automatic microphone mixer incorporates advanced DSP technology. It has been carefully designed to give outstanding performance and flexibility while maintaining simplicity of set up and use. Eight input channels, fully adjustable for microphone and line levels, can be set up to be put onto either or both of the two output channels. Active input channels can be automatically detected. Each input channel can be set to a multi-level priority system.
Features Input Features • • • • • • • • • • • • 8 Channel balanced mic/line inputs on XLR connectors. 48V phantom power selectable for each microphone input channel. Assignable input pairs for stereo sources. Adjustable compressor for each input channel. 2 Band Equalisation on each input channel. Adjustable off attenuation for each channel. Detector modes for speech, music and manual threshold level. Adjustable detector hold time for each input channel.
MR88 Front Panel Controls CLOCKAUDIO MR88 -3 0 +3 +6 O/L Selected Channel Function Power Output Level -20 -10 -6 Channel 1 2 3 4 5 6 7 8 Monitor 1) Power Switch. 2) Display. Displays selected channel/function and settings for each. 3) Channel Buttons. Select between System settings, Output channels A and B, and Input Channels 1-8. 4) Function Buttons. Selects set-up functions for each channel. 5) Rotary Control. Adjusts the settings on each function.
MR88 Rear Panel RS232 External Control Outputs Link Out Link In A B 7 5 8 6 Input Channels 3 1 4 2 Pre-Amp Outputs CLOCKAUDIO Made in EEC-UK DC Input 8 7 6 5 4 3 2 1 1) External Control Connector. Provides access to the open-collector outputs, the external control inputs, and the two VCA connections. 2) RS232 Connector. For control and setup of MR88 mixers. Control extends through link connections to multiple mixers. 3) Link In/Out.
MR88 Menu Functions Navigation through the menu system is via the CHANNEL ( FUNCTION ( menu. Output Ch 1 Channel Mono / A+B Gain Stereo ↔ ) and ↔ ) buttons.
Menu System Output Ch 1 Ch 2 Ch 1 + 2 System Gain Ch A+B -60dB – 0dB Input Type Mono/Stereo Input Type Mono/Stereo Input Type Stereo/Mono Priority 1 mode Inclusive/ Exclusive Gain Ch A -60dB – 0dB Input Level Mic + Phantom /Mic/Line Input Level Mic + Phantom /Mic/Line Input Level Mic + Phantom /Mic/Line Priority 2 mode Inclusive/ Exclusive Gain Ch B -60dB – 0dB Gain -40dB - +20dB Gain -40dB - +20dB Gain Left -40dB - +20dB Priority 3 mode Inclusive/ Exclusive Source Ch A Off/X/Y/ X+Y Gai
Changing Channels and Functions. On power up, if the MR88 is not locked, the channel is set to Output A+B and the function to Gain Channel A and B. Pressing the CHANNEL buttons move forwards and backwards through Channels 1 to Channel 8, System and Output A+B channels. The FUNCTION buttons move up or down through the available functions for each channel. Changing Values. To change the values of each function, simply turn the Rotary Control to display the desired value.
Explanation of Functions Output A+B Functions: Output ChA and ChB Gain. Linked control of the output channels A and B nominal gain. When the >Function button is pressed the ChA gain flashes to indicate independent setting of the output channel A nominal output gain. When the >Function button is pressed again the ChB gain flashes to indicate independent setting of the output channel B nominal output gain.
Compression The task of the compressor is to reduce the dynamic range of the input signal and to control the overall level. The MR88 has a compressor on each of the inputs that can be set to Off, 1 – 8 and Max. These settings vary from 1:1 to 6:1. These can be useful when dealing with large variations of speech input level. On the highest setting even the quietest whisper can be heard at the same volume as the loudest voice. Equaliser EQ Low.
Detector - Adjustable Detector Control Detector. The MR88 gives comprehensive control over channel detection. Channels are connected to the output, dependant on priority setting, when a signal is detected. The method used for detection can be selected by type of input. These are Auto Speech, Auto Music, Manual Level Set, Detector Forced On, and Detector Forced Off.
System Functions: Priority There are 4 levels of priority for the channels. Each priority can be assigned one of two modes: Priority 1 is the lowest, priority 4 the highest. Channels of a higher priority will lock out channels of a lower priority. • • Inclusive mode. - All microphones that are allowed to be active are mixed to the selected output bus. Exclusive mode - "First-come-first-served" mode. Only one microphone can be on at any one time.
Active Control Outputs The MR88 has 8 open-collector outputs, one per microphone channel. These can be used for external control for activating cameras, lights etc. upon detecting speech. The open-collector outputs can sink 500mA each with a maximum collector voltage of +50V DC. This allows a variety of external devices to be driven from the mixer. For extra flexibility the MR88 can be set so that these outputs are either HIGH or LOW when the channel is active. Examples 1.
3.
Control Inputs Each channel has a force closure input to 0V. This menu sets the sense of the closure switch. Force Off means that a shorting switch would force a channel off. Force On means that a shorting switch would have to be closed to allow a channel to be active. Any channel can only become active if the detector and priority allow it to.
VCA - Control Output Gain can be controlled by the external VCA’s connected to the External Control Port. External potentiometers of 10k linear are required. These will provide 0 to 60 dB of attenuation from the output gain setting in the Output Gain menu.
External Control Port Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Function Control Out 1 Control Out 3 Control Out 5 Control Out 7 Control In 8 Control In 6 Control In 4 Control In 2 Gnd (Chassis) +5V Output ( 100mA Max ) VCA 1 Wiper VCA 2 Top VCA 2 Gnd (Chassis) Control Out 2 Control Out 4 Control Out 6 Control Out 8 Control In 7 Control In 5 Control In 3 Control In 1 Gnd (Chassis) VCA 1 Top VCA 1 Gnd (Chassis) VCA 2 Wiper Page 18
Link In/Out - Daisy Chain Capability When more than eight microphones are needed, the MR88 can be daisy chained via the Link In/Out connectors, with other MR88 mixers. This will create a multi-mixer system with audio and control passing throughout the system. All audio and control data is carried by link cables, from 8 pin RJ45 connectors at the rear of the mixer. (This is a 1 to 1 link ) This must be a screened CAT 5E cable.
Installation 1. If rack mounting, fit the mixer to the rack before commencing with the rest of the set-up. 2. Connect 15 V DC power supply provided to the 2.1mm DC connector on the rear panel. 3. Turn the mixer on using the Power switch on the front panel. Basic Set-up for Microphones 1. Connect a microphone to any input channel. 2. Using the CHANNEL button select the appropriate channel. 3. Use headphones in the Monitor Socket. 4. Select Mono or Stereo. 5. Select Level as appropriate.
Security Mode To ensure the mixer setting are not accidentally altered or deliberately tampered with, the mixer has an adjustable 4-digit security code. When the mixer is "Locked", the only way to "Unlock" it is to re-enter the security code. Even if the mixer is switched off and on again, the mixer will re-enter locked mode and still require the security code to be entered. How to Change the Security Code: In the System menu press the function button until the unlock code is displayed.
Specifications Input Impedance 2.4kΩ Differential Output Impedance Balanced 50Ω Pre-Amp Out 560Ω Max Input Level Mic Level -23 dBV Line Level +16 dBV Max Output Level +19 dBV Nominal Output Level at 0 dB on Meter Pre-amp Out -10 dBV Balanced -60 dBV to +4 dBV (Level set on front panel) Frequency Response 20Hz to 20kHz THD+N -70 dB Max NOMA Attenuation 20 dB Phantom Power +48V Power Supply 15Vdc 3.4A External Power Supply with 2.1mm connector.
