Review: RTW's Loudness Tools & Mastering Tools
Mike Swittel
Issue: October 1, 2016

Review: RTW's Loudness Tools & Mastering Tools


PRODUCT: Loudness Tools & Mastering Tools

P RICE: Loudness Tools: $249; Mastering Tools: $549


- Designed to assist with measuring volume proportion, frequency distribution and loudness standards
- Host of “instruments” such as Peak Program Meter, Loudness Sum bar graph, Vectorscope and Real Time Analyzer
- Both programs come ready to go with presets for various listening standards and formats

During the initial push to crossover from analog to digital, many audio users were faced with an awkward new experience. Staring at a computer screen to “hear” audio rather than just using one’s ears. Yes, meters were important, but often the engineer’s experience would override the logic behind the color bars. However, with RTW’s Loudness Tools and Mastering Tools software, the gap between communicating complex technical data and user-friendly functionality has been bridged.

RTW hardware units have always had a solid reputation as being some of the best, most reliable metering solutions in the industry. With the new release of RTW’s Loudness Tools and Mastering Tools software, they are now available in software form as a stand-alone program, including all current plug-in formats for Windows or Mac. As expected, their software versions do not disappoint.

In general, RTW’s Loudness Tools and Mastering Tools are designed to assist the user primarily with measuring volume proportion, frequency distribution and loudness standards to ensure appropriate compliance for radio and TV broadcasts, including target guidelines for cinema. In this update, they’ve also addressed perceived loudness and “annoying volume” compliance for trailers (TASA) and advertisements that precede features in theaters (SAWA). With these tools, RTW seeks to empower the engineer of all skill levels to specifically tweak their productions and maintain accuracy across all mediums, even beyond R128 — the generally accepted target for most applications. 


RTW Loudness Tools includes a host of “instruments” beginning with a Peak Program Meter (PPM) incorporating true peak for up to eight channels usable as a bar graph or numerical display. A Loudness Sum bar graph is also included with measurements for loudness acc. to EBU R128 s1, ATSC A/85, ITU-R BS.1770-3/1771-1, ARIB, OP-59, AGCOM, as well as the CALM Act. The Loudness Num display indicates mono, stereo or integrated time including loudness range or the maximum values across channel counts. And for a graphical representation, the user can also choose the dedicated Loudness Range (LRA) to indicate any variances in the program material. 

RTW Mastering Tools extends the instrument set past the Loudness Tool’s Stereo Correlator and offers a Multi-Correlator intended to check the phase on all available stereo pairs within a Surround mix. The Surround Sound Analyzer (SSA) also provides immediate, intuitive visual analysis of a user’s surround mix balance. Lastly, an audio Vectorscope (VSC) and Real Time Analyzer (RTA) can also be found with the RTA splitting between 1/3, 1/6, and 1/12 octave display.


As an indispensible time-saver, both software programs come ready to go with useful presets addressing various listening standards and formats such as voice-overs, radio spots, feature films and TV commercials. At the same time, user customization is plentiful. What gets displayed, how it is displayed, its vertical or horizontal positioning, as well as a host of specific details per tool makes it extremely versatile. Even instrument colors, sizes, weighting and tolerances are easily accessible for immediate adjustments. In fact, it even allows you to save your favorite configurations based on the type of session you are working on and what format you may be working in. I found this extremely useful when switching between both long- and short-format indie film examples with various intended release mediums, and music-only projects having a completely different set of needs.

What I found most useful was the ability to comfortably verify average long-term levels while tailoring certain sections that called for a bit more excitement. In the upcoming full-feature film, Loving Till It Hurts, I was nearly able to “see the future” while working on the present. This allowed me to push the envelope on more intense, emotional sections and still fall within the guidelines of the respected loudness requirement. With that logic built in, the software nearly became a partner in the project rather than simply a sterile reference tool.

I also enjoyed applying multiple instances across various aux sub-mix channels including the sound effects sub-master to check for any processing phase issues. Doing this allowed me to quickly verify the location of the returns relative to the center image. 

On future versions, I hope RTW will tweak the readout for the PPM, Loudness Sum and LRA to include a minus sign for negative values on the bar graph display or make the zero line slightly more prevalent. Doing this would assist the user when doing quick visual reference checks of the meter location. 


Both RTW’s Loudness Tools and Mastering Tools make powerful additions to any production arsenal. With so many delivery mediums available today, RTW provides a level of confidence that your product will address current industry loudness restraints. Regardless of the user’s experience, these tools will help you achieve a sense of assurance with ease