Secondary Windows Reference

• INPUT: Allows a +/- 10dB change in the incoming audio level to the Downward Expander. Most of the time, you will want to leave this at 0dB.


• OUTPUT: Allows a +/- 10dB change in the outgoing audio level from the Downward Expander. Most of the time, you will want to leave this at 0dB.


• ATTACK THRESHOLD: Sets the level on the Program Input at which the Downward Expander fully opens the channel so that there is no gain reduction of the Program Output. As your performers talk, play, or sing into the microphone, watch the Program Input level. Set the Attack Threshold at a point where any time the local performers initially make a sound, the Program Input level rises above the Attack Threshold, but when they are not making a sound—yet sound is coming from the remote site through the loudspeakers—the Program Input level does not rise above the Attack Threshold. Turning the ATTACK THRESHOLD knob, as well as dragging the green Threshold indicator, will adjust the Attack Threshold level.


• RATIO: Determines the amount of volume change that will occur when the Program Input falls below the Release Threshold level. A setting of 1:2 means that for every 1dB the incoming audio level drops below the Release Threshold, the outgoing audio level is dropped 2dB. A setting of 1:4 means that for every 1dB the incoming audio level drops below the Release Threshold, the outgoing audio level is dropped 4dB. Larger ratios produce a greater effect, but may become noticeable at extremely high settings.


• ATTACK: Sets the speed (in milliseconds) at which the Downward Expander will disengage when the Program Input rises above the Threshold level. To avoid missing the beginnings of sounds you will usually set this from 0.1ms to 1ms.


• RELEASE THRESHOLD: Sets the level on the Program Input at which the Downward Expander begins to apply gain reduction to the Program Output. Set this at a level lower than the Attach Threshold to allow for your performers to play at softer levels without triggering gain reduction. When your performers stop making sound, the level should drop below the Release Threshold. Turning the RELEASE THRESHOLD knob, as well as dragging the red Threshold indicator, will adjust the Release Threshold level.


• HOLD: Sets the amount of time the Downward Expander waits once the Program Input level drops below the Release Threshold before applying gain reduction to the Program Output. Longer Hold times will allow for slow decays of sound, but might allow echo to begin getting through.


• RELEASE: Sets the speed (in milliseconds) at which the Downward Expander will engage when the Program Input falls below the Threshold level. To allow for a natural-sounding decay, settings in the 100ms-500ms range usually work best.


• BYPASS: When on (button is illuminated), disables the Downward Expander so that audio passes through unchanged. You can also disable the Downward Expander from the main Mixer by Option/Alt-clicking the EXPANDER button on the channel strip.


• PRESET: Opens the Preset window allowing you to load, edit, save, and create preset configurations for the Downward Expander. The Preset window works exactly like the Configuration window for the main Mixer.
  • The Downward Expanders all share the same presets. Saving, creating, or deleting a preset in one Expander will have the same result in all Expanders.


• Program Input LED Meter: 33-segment meter indicating the audio input level from the microphone. Each segment represents approximately 3dB. The first green segment illuminates when the audio level reaches -96dBfs, and the meter turns from green yellow at -12dBfs. It turns from yellow to red when the audio level reaches or exceeds 0dBfs. The pointers along the side of the meter indicate the Threshold level.


• Program Output LED Meter: 33-segment meter indicating the microphone's audio level after being processed by the Expander. Each segment represents approximately 3dB. The first green segment illuminates when the audio level reaches -96dBfs, and the meter turns from green yellow at -12dBfs. It turns from yellow to red when the audio level reaches or exceeds 0dBfs.


• Gain Reduction LED Meter: 33-segment downward-reading meter. Each segment represents approximately 3dB of gain reduction between the incoming audio level and the outgoing audio level.

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2-Channel Ducker
The 2-Channel Ducker is accessed by clicking the DUCKER button at the upper-right of the Mixer window. The 2-Channel Ducker is used to prevent your own sound from echoing back to you by automatically lowering the level of the incoming codec audio when your performers talk, play, or sing. The Ducker works with the Sidechain Delay so that it waits until your audio is about to echo before lowering the incoming codec audio level. The Sidechain Delay is calculated using the Latency Detector. For tips on using the 2-Channel Ducker, please see the Controlling Incoming Echo section on the Using the ECHODamp Software page.

2-Channel Ducker Controls

• INPUT: Allows a +/- 10dB change in the incoming audio level to the Sidechain Input. Most of the time, you will want to leave this at 0dB.


• OUTPUT: Allows a +/- 10dB change in the outgoing audio level from the 2-Channel Ducker. Most of the time, you will want to leave this at 0dB.


• THRESHOLD: Sets the level on the Sidechain Input at which the 2-Channel Ducker begins to adjust the level of the Program Input. As your performers talk, play, or sing into the microphone, watch the Sidechain Input level. Set the Threshold at a point where any time your performers make a sound, the Sidechain Input level is above the Threshold, but when they are not making a sound—yet sound is coming from the remote site through the loudspeakers—the Sidechain Input level is below the Threshold. Turning the THRESHOLD knob, as well as dragging the Threshold indicators, will adjust the Threshold level.


• REDUCTION: Determines the amount of volume change in the Program Input that will occur when the Sidechain Input rises above the Threshold level. A Reduction of 10dB means that when the Sidechain Input rises above the Threshold, the Program Input from the remote site will be reduced by 10dB. Larger Reduction amounts produce a greater effect, but may become noticeable at extremely high settings.


• ATTACK: Sets the speed (in milliseconds) at which the 2-Channel Ducker will engage when the Sidechain Input rises above the Threshold level. Settings in a range of 10-50ms usually work best. If the ATTACK time is too slow, you may begin hearing your echo return to you from the remote end.


• RELEASE: Sets the speed (in milliseconds) at which the 2-Channel Ducker will disengage when the Sidechain Input falls back below the Threshold level. Settings in the 50-200ms range usually work best. If the Release time is too fast, you will begin to hear the audio pumping as the level rapidly turns itself back up during momentary pauses or breaths. If the Release time is too slow, you may cut off sounds coming from the remote end.


• BYPASS: When on (button is illuminated), disables the 2-Channel Ducker so that audio passes through unchanged. You can also disable the 2-Channel Ducker by Option/Alt-clicking the DUCKER button on the main Mixer.


• PRESET: Opens the Preset window allowing you to load, edit, save, and create preset configurations for the 2-Channel Ducker. The Preset window works exactly like the Configuration window for the main Mixer.


• Sidechain Input LED Meter: 33-segment meter indicating the audio level of the microphones sent to the Sidechain bus. Each segment represents approximately 3dB. The first green segment illuminates when the audio level reaches -96dBfs, and the meter turns from green yellow at -12dBfs. It turns from yellow to red when the audio level reaches or exceeds 0dBfs. The pointers along the side of the meter indicate the Threshold level.


• Program Input LED Meters: A pair of 33-segment meters indicating the level of the incoming codec audio. Each segment represents approximately 3dB. The first green segment illuminates when the audio level reaches -96dBfs, and the meter turns from green yellow at -12dBfs. It turns from yellow to red when the audio level reaches or exceeds 0dBfs.


• Program Output LED Meters: A pair of 33-segment meters indicating the codec's audio level after processing by the Ducker. Each segment represents approximately 3dB. The first green segment illuminates when the audio level reaches -96dBfs, and the meter turns from green yellow at -12dBfs. It turns from yellow to red when the audio level reaches or exceeds 0dBfs.


• Gain Reduction LED Meters: A pair of 33-segment downward-reading meters. Each segment represents approximately 3dB of gain reduction between the incoming audio level and the outgoing audio level.

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Hi Pass Filter
The Hi Pass Filter is accessed by clicking the HI PASS button at the top of each input channel in the Mixer window. The Hi Pass Filter is used to reduce and eliminate low-frequency noise and rumble that might be picked up by the microphones due to things like breaths, air conditioning, wind, or microphone handling. It is also useful for reducing the low-frequency boost known as the proximity effect when some microphones are placed very close to a sound source.

Hi Pass Filter Controls

• BYPASS: When on (button is illuminated), disables the Hi Pass Filter so that audio passes through unchanged. You can also disable the Hi Pass Filter from the main Mixer by Option/Alt-clicking the HI PASS button at the top of each input channel.


• SLOPE: A 4-position switch that selects the steepness of the cutoff curve below the cutoff frequency in 6dB per Octave increments (-6dB/Octave, -12dB/Octave, -18dB/Octave, -24dB/Octave). Click the slope shape to move the knob to that position. The Hi Pass Filter uses a pseudo-Butterworth design to maintain a flat response above the cutoff frequency as the steepness of the slope changes below the cutoff frequency. A shallower slope will sound more natural, but may not remove as much low-frequency noise as desired. A steeper slope will be more effective, but may remove too much of the desired low frequencies.

-6dB/Octave Slope	-12dB/Octave Slope	-18dB/Octave Slope	-24dB/Octave Slope

• CUTOFF: Adjusts the frequency at which the Hi Pass Filter begins attenuating low frequencies. The range is sweepable fro 20Hz to 250Hz. Like the slope, setting the cutoff frequency low will sound more natural, but may not remove as much low-frequency noise as desired. Setting the cutoff frequency higher will be more effective, but may remove too much of the desired low frequencies.

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Monitor Controls
The Monitor Controls window is accessed by selecting Monitor Controls... (Cmd/Ctl-M) from the Setup menu. If you have the appropriate hardware configuration, the Monitor Controls window allows you to have separate mixes—independent of the mix in the main Mixer window—for the control room and for an audience.

Monitor Controls
The Monitor Controls window is divided into two halves with identical controls in each half. The upper half creates a mix for the Control Room outputs (5 & 6) on your audio interface and the lower half creates another mix for the Audience outputs (7 & 8) on your interface.

• Channel Fader Knob: Adjusts the level of a specific channel sent to its respective Mix (Control Room or Audience) output assignment. When the knob is set to 0.00dB, the signal from the Mixer fader is passed at the same level as in the Mixer. Turning the knob higher than 0 boosts the signal to its output to a level above that in the main Mixer window. Likewise, settings below 0 reduce the signal to a level below that in the main Mixer. Double-click the knob to set it to 0.00dB.


• Mix Fader Knob: Adjusts the overall level of the particular Mix (Control Room or Audience) output. Double-click the knob to set it to 0.00dB.


• MUTE Button: When on (button is illuminated), silences that particular Mix (Control Room or Audience) output.
  
  
• LED Meter with Clip Indicator: A pair of 15-segment peak-reading meters with clip indicators show the output level for that particular Mix (Control Room or Audience). The first green LED segment illuminates at -60dBfs, and the meter turns from green to yellow at -12dBfs, yellow to orange at -1dBfs and orange to red at 0dBfs. If the incoming audio level exceeds 0dBfs, the Clip Indicator will light and remain illuminated for 5 seconds following the clip. You can also turn off an illuminated Clip Indicator by clicking it with the mouse.
  
  
• PRE/POST Button: Determines whether Channels 1-2 & 5-8 are sent to their respective Mix (Control Room or Audience) output assignments before or after being processed by the Downward Expander. For channels 3 & 4, the button determines whether they are sent before or after being processed by the 2-Channel Ducker. For the Control Room, it will probably be helpful to have all the channels set to POST so that you can hear the effect the Expanders are having on the signal being sent to the remote site as well as the effect of the Ducker on the sound your local performers are hearing. For a live audience, it may be preferable to have the all the channels set to PRE for a more natural sound in the audience loudspeakers.

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Calibration Tools
The Calibration Tools window is accessed by Calibration Tools... (Cmd/Ctl-T) from the Setup menu, and is divided into two sections. The Audio Calibration tool at the top allows users to ensure matching audio levels at both ends of the VTC. The Latency Detector tool is used to calculate round-trip latency through the entire system including codecs, audio components, and the network. For tips on using the Calibration Tools, please see the Calibrating Your Audio page.

Calibration Tools Controls

• MODE Buttons: Select whether the Audio Calibration tool is in Transmit (Tx) mode or Receive (Rx) mode.
  Note: Pressing either the Tx or Rx buttons will cause the channel faders on the Mixer to move. This is done to prevent unwanted feedback. When you de-select a button, the Mixer will be returned to the settings you had before clicking either of the buttons.


• TONE Button: When on (button is illuminated), transmits a continuous 1kHz tone at -12dBfs to the remote codec.
  

• INPUT: Selects the microphone Input to be used for the Latency Detector test (you must select a microphone Input before selecting a mode)


• MODE Buttons: Select whether the Latency Detector tool is in Transmit (Tx) mode or Receive (Rx) mode
  Note: Pressing either the Tx or Rx buttons will cause the channel faders on the Mixer to move. This is done to prevent unwanted feedback. When you de-select a button, the Mixer will be returned to the settings you had before clicking either of the buttons.


• ARM TIMER Button: When on (button illuminates yellow and text changes to ARMED), arms the timer. As the test runs, the button illuminates green and its text changes to TIMING. Once the latency time has been calculated, the timer will automatically turn off and the button will return to its original state.


• BEEP Button: Triggers a brief -1dBfs 1kHz tone from the left loudspeaker
  • WARNING: the BEEP button emits a loud 1kHz tone from the left loudspeaker. Please use caution when pressing this button to prevent hearing damage to those in proximity to the loudspeaker.


• SENSITIVITY Knob: Adjusts the sensitivity of the input microphone to ensure that it captures both beeps


• BEEP LEDs: Each LED flashes as the Latency Detector receives first the Local and then the Remote beeps. These flashes indicate that the timer will be able to do the necessary calculation. If one, or both LEDs fail to flash, adjust the SENSITIVITY KNOB until both LEDs flash.


• LATENCY OFFSET Knob: Subtracts a small amount of time from the round-trip latency calculation to compensate for the fact that some VTC systems experience a slight drift in latency time over the course of a session.

Overview, Installation, Setup, and Configuration | Calibrating Your Audio | Using the ECHODamp Software
Menus and Mixer Window Reference | Secondary Windows Reference

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