Working with LevelView
LevelView offers a variety of meters that will be described more extensive in the “Detailed Operation of the Plugin” section of this manual.
Loudness meters measure from start to stop and therefore LevelView first needs to be activated by clicking the ‘play’ button. You can also click the ‘MANUAL’ button, which will then show the word ‘AUTO’. This activates the “Automatically follow DAW transport” function of LevelView. A second click on the button turns on ‘LINK’. All intermediate loudness values while playing along the time line are now stored. If after a first run the play cursor of the DAW is placed somewhere back on the time line, LevelView’s graph reflects the local history, but the numeric readings show the full program values. In case you now change your mix, the numeric results of the full program length are shown right away, freeing you of the need to re-measure your audio.
The main meter is a ‘rainbow’ like meter, inspired by the ‘Bendy Meter’ concept proposed by BBC Research. It shows several integration times in one glance, which means you can read the average level of the last 3s (“S” or Short term), 10s, 30s, 90s and 270s. This way you can react to short term dynamics variances while anticipating at an average loudness level over a longer time.
In the outer ring, the relatively fast (400ms integration time) ‘M’ or Momentary meter is shown. It gives instant feedback of the current subjective loudness level. The M meter of LevelView is modelled on vintage light spot meters. It offers a view with continuos brightness, which is less fatiguing for the eye than the rapidly changing light intensity of a bar graph meter. The M and S meters have a peak hold function. The scale of the bendy meter can be switched between ‘EBU +9’ scale and ‘EBU +18’ scale by clicking on the meter surface. Mark that with loudness meters, levels will regularly modulate above 0 LU. Since the target at the end of the program is 0 LU, one should modulate approximately an equal amount of sound above 0 LU as below it. Experience has for instance shown that properly modulated dialog has an S level that is allowed to vary between -7 LU for whispering and +7 LU for loud shouts. On average, dialog should modulate around 0 LU.
The big number on the right hand side is the ‘I’ or Integrated loudness. It displays the LUFS level, which is relative to full scale. For EBU R128 recommendation compliance, this number needs to become -23 LUFS at the end of your mix. The 0 LU level of the bendy meter (at the top) is aligned to this level. For ATSC A/85 compliance, the number needs to be -24 LUFS and this 0 LU calibration is selected by clicking the ‘EBU’ text, which then changes to ‘ATSC A/85’. By clicking another time, the meter enters ‘User’ mode, with an adjustable 0 LU level and gate.
Broadcast and post production engineers in the US know that according to the ATSC recommendation A/85 they need to adjust the volume of their program based upon analysis of the dialog parts only. This is conveniently done using LevelView. The 2009 edition of ATSC A/85 has no ‘relative gate’ in the measurement and a target of -24 LKFS (= LUFS) in stead of -23 LUFS like in EBU R128. In its ATSC setting LevelView complies to that standard. Since the ITU has adopted the EBU R128 relative gate in 2011, it is now unclear if ATSC A/85 advices to measure ‘all with gating’ or dialog only. Grimm Audio will closely follow the developments. Mark that moving loudness meters like LevelView’s bendy meter do not use the relative gate: the user should have a view of all levels. Only the integrated (I) loudness level is gated.
Below the big ‘I’ number there is a table showing the measurement results of four loudness descriptors, defined in EBU R128: max S, max M, LRA and max TP. Max S and max M reflect the peak hold readings of the bendy meter (the maximum Momentary level and the maximum Short term level). LRA stands for ‘Loudness Range’, which gives an indication of the spread of loud and soft parts in the program, and max TP stands for ‘maximum True Peak level’. By clicking max TP, it changes to max SP, which stands for ‘maximum Sample Peak level’. When the levels exceed certain limits, the numbers will turn orange.
In the left hand corner a histogram of measured Short term levels can be found: soft parts on the left, loud parts on the right. The LRA is calculated from this data and the grey area shows the LRA span within the histogram. The vertical white line shows the current ‘I’ level. The blue line shows the current level of the relative gate (10 LU below the ungated loudness). The small moving red marker below the histogram shows the current S level.
Clicking the Grimm logo in the upper left corner opens the info page of LevelView where you can see the version number, credit list and licence.