One popular application for the Logic Box or Voltage Control Box is to interface with conferencing microphones that feature mute switches and LED indicators, and Shure is a leading manufacturer of such microphones. This article describes how to physically connect a Shure MX395-LED microphone to a Biamp Logic Box.
After completing the steps in this article, you will be able to connect a Shure MX395-LED to a Biamp Logic Box. This will allow your Audia or Nexia configuration to control the LED's on the MX395-LED.
Note that Shure MX series microphones use phantom power to power its LED's. Therefore, no external power supply is required for this application.
The Shure MX395-LED is a boundary microphone with a bi-color LED ring. The MX395-LED comes with a 5-pin XLR connector. The pinout of this connector is shown in the table below:
|Pin 1||Audio Ground|
|Pin 2||Audio -|
|Pin 3||Logic Ground|
|Pin 4||Audio +|
|Pin 5||LED In|
The audio conductors on the microphone will connect to the audio inputs on the Audia/Nexia like a typical microphone. The LED and Logic Ground conductor will connect to the Logic Box. The LED In conductor connects to a logic output, and the Logic Ground connects to any of the ground terminals on the Logic Box.
Each MX395-LED uses one logic input terminal on the Logic Box, which means that a maximum of 20 MX395-LED's can be connected to a single Logic Box. The diagram below shows a typical wiring scheme for a single MX395-LED:
The microphone's LED ring will light up green when there is less than 1V across pins 3 and 5 (i.e., logic output in the low state), and it will light up red when there is 5V across pins 3 and 5 (i.e., logic output in the high state).
Once the device is physically connected to the Logic Box, you'll need to program it. See Logic Box Programming for more information.