Aura Help Center

Bar

The Bar meter uses a strip of colorful LED-like segments to indicate a signal level

Bar meters are constructed from any number of “modules” - bars, rulers, and spacers. The bar modules can contain any number of traces to display a signal level. The traces can be displayed as a strip of segments, single segments, pointers along the edges of the bar, or a peak light at the top of the bar.

Controls

Hover the mouse over the meter to reveal the control bar.
Show the meter configuration popover
Show the modules & traces configuration popover
Pause the meter
Run the meter
Reset the meter values

Meter Configuration

  1. The background color
  2. The direction of the meter
  3. The width of the bar modules
  4. The size of the segments in the bar modules
  5. Select to display the bar module names at the base of the module
  6. The scaling method for the magnitude traces
    • Logarithmic: magnitudes are positioned at logarithmic intervals from 0 to -120dB
    • Linear: magnitudes are positioned at linear intervals
    • Split: magnitudes are positioned linearly above -20dB and logarithmically below -20dB
  7. The amount to zoom in on the range above -20dB

Modules & Traces Configuration

  • There are three types of modules: Bar, Ruler, and Spacer
  • There are three types of traces: Magnitude, Loudness, and Peak
  • Bar modules can contain one or more traces
  • All traces or modules can be configured independently or as a group

Modules

Modules can be considered separate physical sections of a Bar meter. They are ordered from top-to-bottom, or from left-to-right if the orientation of the meter is vertical.

Bar

Bar modules contain a strip of LED-like segments
  1. The audio inputs for all of the traces in the bar
  2. Select to run all the traces. Deselect to pause.
  3. Select to hide all of the traces.

Ruler

Ruler modules mark the locations of signal values
  1. The ruler scale
    • Standard: uses the magnitude with respect to 0dBFS
    • VU: classic VU scaling where 0dB = -14dBFS
    • Program Loudness: uses the LU +18 scale from -36 to +18 LU. Range scaling does not affect this ruler.
    • UK/BBC: uses a custom numbering system from 1 to 7
    • EBU: 0dB = -18dBFS, 0dB is labeled “test”, and major labels are in intervals of 6dB
    • DIN: 0dB = -9dBFS
    • Nordic: similar to EBU except that major labels are in intervals of 4dB
    • K-20: 0dB = -20dBFS
    • K-14: 0dB = -14dBFS
    • K-12: 0dB = -12dBFS
  2. The size of the ruler text
  3. The direction the text will be written
  4. Select to display ruler hatches on the top/left side of the module
  5. Select to display ruler hatches on the bottom/right side of the module

Spacer

Spacer modules are simply blank space. They are used to separate modules from each other visually.
  1. The size of the space

Magnitude Trace

Magnitude traces are displayed in the segment strip of a bar module and measure the magnitude of a signal in dB.
  1. The audio inputs to combine.
  2. The method used to combine the channels.
    • Sum: adds the samples together
    • Difference: even numbered channels are subtracted from odd numbered channels
    • Average: the samples are added together and divided by the number of channels
    • Average Difference: even numbered channels are subtracted from odd numbered channels and the result is divided by the number of channels
  3. The amount of gain to be added to the combined result.
  4. The mathematical algorithm to use to quantify the set of audio samples.
    • Peak: The maximum magnitude
    • TruePeak: The maximum magnitude after a high-definition upsampling
    • RMS: The root-mean-square
    • AES-17: The root-mean-square value + 3dB
    • Average: The mean
  5. The response rise and fall time.
  6.   Rise Time Hold Time Fall Time
    Digital 9.5dB in 1.7ms none 20dB in 850ms
    PPM Type I 9.5dB in 1.7ms none 20dB in 1.7s
    PPM Type II 9.5dB in 1.7ms 100ms 24dB in 2.8s
    VU 40dB in 300ms none 40dB in 300ms
    Nordic 14dB in 5ms none 20dB in 1.5s
    BBC/EBU 14dB in 5ms none 24dB in 2.85s
    Peak Hold (Short) immediate 0.7s 60dB in 300ms
    Peak Hold (Long) immediate 2.0s 60dB in 300ms
    Peak Hold (Infinite) immediate forever none
  7. The display style
    • Segments: consecutive segments from -∞ to the value
    • Single Segment: the single segment closest to the value
    • Pointers: small triangles on both sides of the edge of the bar
  8. The color gradient. A sample of the color set is in the trace's row in the trace list.
  9. Select to run the trace. Deselect to pause.
  10. Select to hide the trace.

Loudness Trace

Loudness traces are displayed in the segment strip of a bar module and measure the Program Loudness of the signal.
  1. The audio input that contains the left channel content.
  2. The audio input that contains the right channel content.
  3. The audio input that contains the center channel content.
  4. The audio input that contains the left surround channel content.
  5. The audio input that contains the right surround channel content.
  6. The time scale for the program loudness measurement
    • Momentary: a non-gated time window of 0.4s
    • Short-Term: a non-gated time window of 3.0s
    • Integrated: the gated accumulated value
  7. The display style
    • Segments: consecutive segments from -∞ to the value
    • Single Segment: the single segment closest to the value
    • Pointers: small triangles on both sides of the edge of the bar
  8. The color gradient. A sample of the color set is in the trace's row in the trace list.
  9. Select to run the trace. Deselect to pause.
  10. Select to hide the trace.

Peak Trace

The Peak Trace is drawn in two segments at the top of the bar and light up when the audio signal is close to or above a threshold.
  1. The audio inputs to combine.
  2. The method used to combine the channels.
    • Sum: adds the samples together
    • Difference: even numbered channels are subtracted from odd numbered channels
    • Average: the samples are added together and divided by the number of channels
    • Average Difference: even numbered channels are subtracted from odd numbered channels and the result is divided by the number of channels
  3. The amount of gain to be added to the combined result.
  4. The mathematical algorithm to use to quantify the set of audio samples.
    • Peak: The maximum magnitude
    • TruePeak: The maximum magnitude after a high-definition upsampling
  5. Select the response rise and fall times.
  6.   Rise Time Hold Time Fall Time
    Digital immediate none 20dB in 850ms
    Analog * 40dB in 300ms none 40dB in 300ms
    Hold (Short) immediate 0.7s none
    Hold (Long) immediate 2.0s none
    Hold (Infinite) immediate forever none
    * The analog response will begin to light the indicator within -6dB of the threshold.
  7. The trace color
  8. Select to run the trace. Deselect to pause.
  9. Select to hide the trace.