MR 88

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 priority system. This allows “one at a time operation”, “all channels active” or busses provided, the MR88 to be used as a genuine 8 X 2 mixer.

The input level control and priority system of this mixer makes it uniquely versatile for many diverse applications. The MR88 mixer is ideal for places of the mixer via a user-friendly LCD interface on the front panel. This allows the mixer settings to be selected and adjusted without the need to remove the from the mains power supply.

The mixer front panel can be easily ‘locked’ with an adjustable four digit security code to prevent the mixer settings being accidentally changed, or to ‘tamper proof’ the settings. The MR88 also has the ability to be daisy chained with other MR88 mixers via a link cable (available separately), to give a multi-mixer system. • 8 Channel balanced mic/line inputs on XLR connectors. • 48V phantom power selectable for each microphone input channel. • 2 Band Equalisation on each input channel. • Detector modes for speech, music and manual threshold level. • Adjustable detector hold time for each input channel. • Four levels of assignable priority for each input channel. • Assignable to either or both output channel busses. • 2 Channel balanced line outputs on XLR connectors. • Independent or linked gain control of output channels. • Mixed output available from any mixers in chain for multi-zone control. • Easy set up with LCD display of all functions and settings from front • LED level meter to monitor any input or output channel. • Monitor headphone output to monitor any input or output channel. • Mixers can be linked to create larger systems of microphones. • Each priority can be set for inclusive (all channels active) or exclusive • Selectable last microphone on operation to maintain ambient sound. • External VCA control of output channel gains. • External logic level control and monitoring of channel selection. 2) Display. Displays selected channel/function and settings for each. 4) Function Buttons.

Selects set-up functions for each channel. 5) Rotary Control. Adjusts the settings on each function. 6) LED Level meter Indicates peak output level of the selected channel in in use and which other microphones are being “locked out” (attenuated). Green is active and Red is locked out. 8) Monitor Volume Control.

Adjusts headphone amplifier volume. 9) Headphone Output. 1/4″ TRS jack. Monitors the selected channel. outputs, the external control inputs, and the two VCA connections. levels of -60 to 0dBV. This can be setup to be controlled by external equipment (CD players etc).

Input gain adjustable from front panel. 48V phantom power can be selected from front panel for microphones. Navigation through the menu system is via the CHANNEL ( ↔ ) and FUNCTION ( ↔ ) buttons. The table below illustrates the structure of the Output to Output to Output to Output to Output to Output to Output to Output to Hold time Hold time Hold time Hold time Hold time Hold time Hold time Hold time 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 To change the values of each function, simply turn the Rotary Control to Output ChA and ChB Gain. Linked control of the output channels A and B 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. to indicate which common bus the local output A should use as its source.

This can be set for Off, Bus X, Bus Y or Bus X and Bus Y to indicate which common bus the local output B should use as its source. This can be set for Off, Bus X, Bus Y or Bus X and Bus Y The MR88 can be set so that Channels 1 & 2, 3 & 4, 5 & 6, or 7 & 8 are considered as a stereo pair. This reduces the number or setups required for a stereo music source.

Each stereo pair has only one setting for Input Level, compression, EQ, Output, priority, gate attenuation, detector and hold time. This sets the nominal input level to mic level + 48V phantom power, mic level The MR88 has a substantial gain range, (-40 to +20dB) allowing the use of a variety of microphones and line inputs. Generally, if the level has been set to level, and the headphone monitor can be used to listen to the channel, so that the gain can be set per channel, even when the channel is not connected to the output.

When set to stereo three functions allow the gain 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 EQ Low. 12dB boost or cut of the low frequency components of the audio signal with this, 200 Hz fixed frequency, shelving filter. This is useful for adding warmth to a microphone or subtracting boom.

EQ High. 12dB boost or cut of the high frequency components of the audio signal with this, 5kHz fixed frequency, shelving filter. This can be useful for Output. Selects if a channel is not used (Off) or goes to Output Bus X, Output Bus Y, or Output Bus X + Y of the mixer.

A pair set to stereo, are treated in almost exactly the same way. When set to Output Bus X, the pair is placed as mono onto output bus X. When set to Output Bus Y, the pair is placed as mono onto the Output Bus Y.

When set to Output Bus X+Y, the pair is placed as mono onto the Output Bus X and as mono onto the Output Bus Y. When set to Stereo output, the lower input channel number of the pair is placed on Output Bus X and the higher input channel number to Output Bus Y. When the output is set to OFF the channel is removed from detection The priority of each microphone channel can be selected using this function.

Each can be set from 1 to 4. Channels set to the higher priority override channels with a lower priority. The mode of operation for channels with the same priority can be set in the system menu.

This can be inclusive or attenuation can be adjusted using the gating level control for each channel. Sets the level of ‘off’ attenuation (6dB – 40dB or muted) for each channel. When the number of microphones in use is high it may be necessary to Detector.

The MR88 gives comprehensive control over channel detection. signal is detected. The method used for detection can be selected by type of Auto Speech detector is an adaptive threshold and is very useful in noisy Auto Music Detector is designed to detect music. Manual Detector Level setting can be set so that the channel triggers on a specific level of sound (-40dB to – 0dB). even when no sound is present.

This can be useful for setting a particular microphone to be the ambient microphone of a system rather that use the “last one on” function, or used in conjunction with external control as a Detector Forced Off is used to make the selected channel never trigger on sound. It can be used in conjunction with external control as a manual mixer. Hold time is the time a microphone channel is below trigger level before it releases the lockout bus.

The Hold time is adjustable with 5 settings. microphones to switch on the slightest break in the speech. Sometimes it is 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 to up to 2 seconds, depending upon application. This feature enables the last microphone channel used to be left switched on until a new channel is detected. This can help to keep a constant ambient sound in a system.

If used in a multiple mixer linked system all mixers need The 4 digit code displayed is the current security code. This can be changed by simply turning the Rotary Control to change each digit and by pressing the For extra flexibility the MR88 can be set so that these outputs are either HIGH or LOW when the channel is active. 2. High efficiency LED’s can be powered from the auxiliary 5V (pin 10) on the control port.

The maximum current allowed from this pin is 100mA. 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.

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 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 Each additional mixer contains the audio from the one previous and mixes its outputs onto the output busses. This total mix is fed back up the chain from the last mixer making the full mixed output available from any of the mixers in practical limit of the number of MR88 mixers that can be daisy chained is 50. The SYSTEM settings for Priority and Last One On should be set to be the same for all mixers in the chain.

If they are set up differently their operation A PC program is available to setup the MR88 without the use of the front panel. In a multi mixer system the RS232 can be plugged into any of the mixers in the system, and the mixer to be set up selected from the program. The MR88’s are automatically addressed from 1 to n when they are linked 1.

If rack mounting, fit the mixer to the rack before commencing with the 2. Connect 15 V DC power supply provided to the 2.1mm DC connector on 3. Turn the mixer on using the Power switch on the front panel. 1.

Connect a microphone to any input channel. 2. Using the CHANNEL button select the appropriate channel. 6. Adjust the Gain so that the Level Indicator peaks at 0dB when speaking 7.

Adjust Compression to get the quietest sounds to the required level. 8. Adjust the EQ Low and EQ High for the required tonal quality. 9. Select Output to Bus X, Bus Y or Both Busses as required. 11.

Set the Gate Attenuation (Off Attenuation) to the level that is required when the microphone is not active. This can be set to between 6dB and 12. Set the Detector Type to Auto speech detection. 14.

Decide if the channel should be included in the NOMA calculation. 16. Select the Output A+B Channels and select the source for the output 17. Select the Output A+B Channel Gain and adjust the ChA and ChB output are –40dBV and for line levels 0dBV or –10dBV.

The channel A and channel B gain controls can be either set together or individually. 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. In the System menu press the function button until the unlock code is displayed.

Use the rotary control and Function Buttons to set the code to the desired value. The default factory code is 1234. To lock the Mixer front panel settings hold down both the <CHANNEL and that the mixer is about to be locked during this 3 seconds.

Releasing the keys will abort the locking process. After the 3 seconds the mixer will display When the mixer is locked it will either display “Locked, Enter Code —-“, or If the security code is lost or forgotten the mixer can be reset to factory buttons held down. This will restore the security code to 1234 and unlock the mixer.

All other settings are also reset, so a full setup procedure must be -60 dBV to +4 dBV (Level set on front panel)