Matrix Mixer
Most things can be controlled from the matrix mixer (part shown below)
There is one for the echo canceller and a smaller one for the phone add. Each input (on the left) has an associated gain control. Each output (on the top) also has a gain control. Each intersection has one, too. So it is possible to configure the Viewstation sound to come mostly from the centre and right speakers and the telephone sound to come mostly from the left speakers, and so on.
A left-click on a gain box pops up a slider; you can type a gain (in dB) or use the slider. A right-click mutes the link (greys it out). Boxes can be ganged together by dragging the mouse and adjusted as a group. The M button on the slider is Mute. The G button on microphone input lines enables the automixer for that output, if one is enabled for that input.
Presets
Mixer settings can be saved in non-volatile RAM in the Vortex. The system is set up to use AG (user 16). If you want to experiment with other settings, please use other presets and restore the system to the AG or AG no XP presets afterwards.
Mic/Line Inputs
The Mic/Line Inputs task controls the phantom power, input levels, echo cancellation (AEC), noise cancellation (NC), and automatic gain control (AGC) for each input.
The ceiling microphones and Shure table microphone use balanced inputs
and need phantom power - a DC voltage supplied via the input cables.
Other inputs do NOT need phantom power and might be damaged. Phantom
power is controlled by the Phan icon - red means on.
The 8 microphone inputs can be used for less sensitive line-level
input (e.g. other equipment, PC output) by setting
the Mic/Line switch and turning off phantom power. The 4 line inputs
can only be used for line-level. Unused inputs can be masked off the
display by selecting the "View Inputs" icons. SG is a
sound generator that can be set to produce either white noise or "pink
noise" (random noise with equal power per octave) for testing filters,
speakers etc.
- Input Controls 1 - VU, AGC
- Inputs Controls 2 - AEC, NC
Filters
The system has configurable multistage filters on both inputs and outputs. For normal use some high-pass and low-pass filters are enabled to cut down on low-frequency room noise (doors closing etc.)Automixer
The purpose of the automixer is to drop the gain on microphones other than the one where someone is speaking, in order to reduce the amount of chatter and room noise that is picked up - papers shuffling, chairs squeaking etc - that the human ear is quite good at ignoring but which electronics faithfully reproduces.The Vortex has two automixers; we use one. The "chairman" designates a microphone that has priority; we may enable the Shure table microhpone as chairman. The "gate" indicators are enabled by the "Levels" control and indicate which microphones are active. "Camera" refers to a logic output that may be used to direct automatic camera panning - we do not have this configured.
Logic Inputs, Macros
The Vortex has about 20 logic-level inputs and outputs that can be configured to respond to certain actions. Multiple actions may be configured into a macro. Currently (Nov 32003), the button on the Shure table microphone is configured to mute all microphones via a logic input and macros "Mute", "Unmute". The LED on the Shure microphone is connected to a logic output and lights when the Shure is unmuted.Currently, two logic inputs are connected to the AG system parallel port and may be used to load predefined presets or poerform some other action.
See also How to Configure the Vortex EF2280 for an Access Grid Node
TRIUMF VideoConferencing
A.Daviel