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Loudness Meter

Red Rock Sound

  • • Multimode loudness measurement meter
  • • Dynamic Range and Loudness Range (LRA) meters
  • • Peak/RMS, Mid/Side, R128,Phase and Overs detection

The Measure is a sophisticated metering and measurement tool that allows you to visually analyze your audio signal in several useful ways.

Product details

Too loud mixes often sound squashed, and in long mixing sessions your ears often get used to the squashed sound so you´re losing objectivity. The Measure will show you Peak and RMS values of your mixes, and in addition to that it will show you the relation between both with the centered DYNAMIC LED's, PHASE correlation between Left and Right, the number of Overs and new measurement loudness mode 'R128' with Loudness Range (LRA). When working with a stereo signal, choose Sum/Diff mode to make sure there is no energy drop in the sum which could be caused by phasing problems and that the difference (diff) is not too low compared to the sum. To save space in your Reason rack, we duplicated 'Max Peack' 'RMS' ‘R128 Mode’ indicators at the front folded panel.

The new design "Black Night Edition" is designed specifically in dark colors, so that you are focused only on the measurement, without being distracted by anything else.

There is a potential for ambiguity when assigning a level on the dBFS scale to a waveform rather than to a specific amplitude, since some choose the reference level so that RMS and peak measurements of a sine wave produce the same number, while others want the RMS and peak values of a square wave to be equal, as they are in typical analog measurements. Measure allows you to select RMS Reference Waveform Sine or Square. For the case in which the RMS value of a full-scale SQUARE wave is designated 0 dBFS, all possible dBFS measurements are negative numbers. A sine wave could not exist at a larger RMS value than −3 dBFS without clipping, by this convention. This is the convention used in Euphonix meters. For the case in which the RMS value of a full-scale SINE wave is designated 0 dBFS, a full-scale square wave would be at +3 dBFS. This is the definition specified in AES Standard AES17-1998 and IEC 61606 and used in Dorrough meters and meters with K-System guidelines.

The new Dynamic Range Meter is calculated from your peak and RMS metering. It shows you how “squashed” (aka “over compressed”) a mix is. To a degree this can indicate how “loud” your mix appears as well. In general, the length of the meter bars show you how much dynamic you have in your signal, if they are short and red, then you should think about... :) In more detail about Dynamic Range:

New measurement mode 'R128' provides precision loudness measurement and metering for broadcast, movie trailers, games, packaged media and more. Fully compliant ITU-R BS.1770-2 and EBU R-128 specifications. An ‘R128 Mode’ loudness meter as defined in EBU Tech Doc 3341 offers 3 distinct time scales:

  • Momentary Loudness (abbreviated “M”) – time window: 400 ms
  • Short-term Loudness (abbreviated “S”) – time window: 3 s
  • Integrated Loudness (abbreviated “I”) – from ‘start’ to ‘stop’

Loudness Range (abbreviated ‘LRA’) quantifies the variation in a time-varying loudness measurement. Loudness Range is supplementary to the main audio measure, Programme Loudness, of EBU R 128. Loudness Range measures the variation of loudness on a macroscopic time-scale, in units of LU (Loudness Units). The computation of Loudness Range is based on a measurement of loudness level as specified in ITU-R BS.1770, albeit with a different relative gating threshold. Loudness Range should not be confused with other measures like dynamic range or crest factor, etc. In more detail about Loudness Range:

Reference Scales:

  • -23: -23dBFS(LUFS for R128 mode)
  • -20K(atz): -20dBFS(LUFS for R128 mode)
  • -18: -18dBFS(LUFS for R128 mode)
  • -14K(atz): -14dBFS(LUFS for R128 mode)
  • -12K(atz): -12dBFS(LUFS for R128 mode)

The phase correlation mode is a standard correlation meter tool to monitor the phases (and potential phase problems!) of your stereo mix/signal.

  • -1 means your mix/signal is “out of phase” (180°).
  • +1 means your mix/signal is “in phase” (0°).
  • 0 (zero) means that there is either:

• no signal present • signal present on only one channel • phases of L&R channels are shifted exactly 90°.

Measure meter are able to detect and display the number of Overs, which are defined as 3 samples or more that exceed 0 dBFS (-0.0008 dBFS).

What is OVERS:

Includes the K-System:


  • Reference scales mode
  • Peak and RMS Level Relations
  • Dynamic Range Meter
  • Measurement loudness mode 'EBU R128'
  • Loudness Range (LRA) Meter
  • Sum and Difference Energies for Optimal Stereo-to-Mono Compatibility
  • Left/Right Phase Correlation
  • Displays Number of Overs
  • Adjustable PPM integration and return times
  • Selectable RMS Reference Waveform
  • Adjustable RMS rise and fall times
  • 40dB Scale in 1 dB steps


New in 2.5.2:

  • Increased size of the device with up 2U to 3U.
  • added Dynamic Range meter on L/R and M/S meter modes
  • added Loudness Range (LRA) on R128 meter mode
  • added Two stereo inputs for Reference audio signals
  • added Hybrid settings (RMS + R128) for R128 meter mode
  • updated digital displays on the front folded panel (now displays Max Peack, RMS and R128 )

New in 2.0.0:

  • reduced the size of the device with up 3U to 2U.
  • added adjustable reference scales modes
  • added measurement mode 'R128'
  • added adjustable PPM integration and return times
  • added adjustable RMS rise and fall times
  • updated digital displays on the front folded panel

New in 1.2.2:

  • Duplicated knob "RMS Averaging Time" on the back folded panel
  • other small fixes and optimization

New in 1.0.2:

  • updated digital displays on the folded front panel
  • added a button reset for max peak on the folded front panel
  • cosmetic improvements

New in 1.0.1:

  • updated LEDs
  • added marking Reference Level (for Sine RMS reference waveform only!) 20dB AES / K(atz)-20 / SMTPE 18dB EBU 14dB K(atz)-14 12dB K(atz)-12



Released: 2017-03-15
Version: 2.5.2