CRR – Control Panel

The Conference Room Router control panel provides simple unified control of all audio signals inside the CRR.

Input Controls
The left side of the CRR control panel shows the Input Controls. This will include one channel for the Program input and one channel for each Far End input. Since each room is different, there may only be a single channel in this section, or as many as nine channels if all eight Far End inputs are being used. These are analogous to input channels on a traditional mixing console and they are used to create the Non-Mic Mix for the CRR. The gain structure of the system should be set up so that setting each of these faders at 0 dB will provide approximately the same output level from all sources.

Changing the level or mute status of any of these channels will affect that audio signal at every output of the CRR.

Master Controls – Non-Mic Mix and Mic Mix
The Non-Mic Mix and Mic Mix channels on the CRR control panel are analogous to sub-master faders on a mixing console. The Non-Mic Mix channel controls the combined level of the Program input and all Far End inputs to every output. This allows an adjustment to be made to the relative level of microphones vs non-microphones which will be exactly the same for every output without needing to individually check each output.

The Mic Mix channel also controls several things simultaneously, but in this case it is controlling different inputs to different outputs. Post-AEC microphone inputs are routed to all non-speaker outputs while Pre-AEC inputs are routed to speaker outputs. Adjusting the Mic Mix fader will adjust the level of both of these routings simultaneously.

If the system gain structure has been set up so that the required relative levels of microphone signals vs non-microphone signals is appropriate for each output, using the Non-Mic Mix and Mic Mix faders will allow adjustments to be made during a teleconference with confidence that the audio will be changed appropriately for every output.

Master Controls – Master Volume
The Master Volume controls are the room volume control and mute. The master volume fader and mute will affect the audio going to every speaker output of the CRR without affecting the Aux and Far End outputs. Changing the master volume in the room will not change the level being sent to the Far End or Aux outputs

The Master Volume control also affects the AEC reference output signal. If the level in the room speakers were changed without also changing the AEC reference level, the AEC would need to re-converge and the far-end would momentarily hear an echo of their own voices. The Master Volume control eliminates this problem by maintaining a proper relationship between the room volume and the AEC reference.

Speaker Matrix
The required routing of audio to speaker outputs varies greatly between different projects and cannot be predicted with rules based on routing assignment. For this reason, audio routing to speaker outputs is controlled by the Speaker Matrix control panel which may be accessed by clicking on the Speaker Matrix button. The Speaker Matrix routing controls are located on a sub control panel because they are only used during the initial setup of the system. Program and Far End inputs are routed by default to either the Front or Overhead speaker outputs depending on the output configuration of the system. This ensures that a valid audio path will exist by default for testing inputs, but routing may be changed as needed based on project requirements.

Various inputs and outputs on the CRR may be mono or stereo. On the speaker matrix control panel, inputs and outputs are always represented by a single crosspoint even if they are a stereo signal. This does not mean the signal has been reduced to mono. It is simply a convenience feature which allows a simpler and smaller control panel that can route a stereo signal to a stereo output with a single button. If a stereo input in the CRR is routed to a mono output, or if a mono input is routed to a stereo output, the CRR automatically performs the required adjustments to signal-level to maintain the same relative mix level with all other signals. By default, this attenuation is the normal 3 dB per channel, but this can be adjusted by right-clicking on the CRR, selecting Stereo Mono Attenuation from the context menu, and selecting a different value.