Mastering audio today involves more than just creating loud and exciting stereo music masters. The mastering engineer takes on the roles of quality control, metadata oversight, and of course, producing impressive sounding, competitive audio. The NUGEN Audio Modern Mastering Bundle combines three sophisticated plug-ins that each play a vital role in creating masters in the modern world of audio production for music, podcasts, audiobooks, and multimedia. The three plug-ins, each one available as AAX, RTAS, VST2, VST3, and AU versions, provide level control and several different types of audio analysis, from visual analysis of levels and imaging, to visual and audible level comparisons of your master to various streaming standards. These are professional tools, and you will benefit from spending a good amount of time learning to use each plug-in. I have used NUGEN plug-ins for a few years now, and have found that by learning about and applying these plug-ins, I have developed a better sense of the applications of audio levels and feel I can easily meet the expectations of content producers, distributors, and, ultimately, the intended audience.
The most utilitarian plug-in of the Modern Mastering Bundle is called ISL True Peak limiter. Essentially a mastering limiter, or maximizer, ISL provides an inter-sample True Peak limiter with comprehensive and flexible metering along with dithering. The ISL provides an input gain control, and a separate true-peak limit, or ceiling control. The limiter activity is displayed via three metering sections. The first section displays the post input gain stereo input levels. The second meter displays the amount of gain reduction as one of two user-selectable display styles. The output meters display the resultant stereo output levels as dBFS (True-Peak). NUGEN provides further metering options, called Steering and Ducking, which display the byproducts or interaction between left and right channels as one or both channels trigger the limiting action. Steering and Ducking work along with and are affected by the Linking function of the limiter. Additional controls affect lookahead, release time, comprehensive dither, and noise shaping options. ISL thoughtfully provides the ability to listen to the difference signal, or gain reduction effects only, of the limiting process to help fine-tune the processing against any undesirable artifacts. NUGEN has provided presets that comply with ITU-R BS.1770, and Apple's afclip standards that offer the ability to create level compliant masters for iTunes, Netflix, or any other streaming or broadcast standard. It should be noted that the ISL meter is designed as a True Peak meter (not a traditional loudness meter), which measures the highest point of an analog signal, versus a Sample Peak meter, which evaluates only the digital signals, as it has become important to closely monitor peak levels for the best possible conversion to lossy codecs, like MP3.
The MasterCheck plug-in provides a more traditional loudness metering and level optimization, geared towards music mastering as well as streaming services that use proprietary data compression and loudness matching algorithms. MasterCheck provides metering for loudness monitoring (LUFS/LKFS), dynamic range (PLR/PSR), real-time comparison to reference tracks (via the NUGEN Send plug-in), codec preview functions and true-peak level compliance metering (ITU, afclip). The MasterCheck meter has been my go-to meter when mastering for the last couple of years, and I have benefited greatly from its features.
The basic meter functions include K-level metering via the LKFS displays, Peak to Loudness Ratio metering, program loudness metering, mid/side levels, true-peak levels, and an assignable external reference input, which allows a separate reference audio track level to be displayed inside the MasterCheck plug-in. All these metering displays have accompanying preference settings for behavior and display options and will be familiar to anyone who has used mastering meters. MasterCheck also provides a sophisticated Codec Monitoring section, which essentially allows the user to meter or monitor the audio stream as encoded by many different streaming services, including Spotify, Tidal, iTunes, BBC iPlayer, and many others. Since each service plays audio using a specific codec and audio level, MasterCheck shows an instant comparison of the DAW audio to a specific service's profile and allows you to create an optimized version of the master for a particular use. In practice, I find it informative to audition these codecs, but many of my clients do not have the ability to provide optimized masters to each platform, as the clients use an aggregator like DistroKid, to distribute to several services. It is still helpful to audition and be aware of level and codec differences between services. Occasionally it is valuable to optimize a program for a specific platform, such as in audiobook or podcast preparation.
MasterCheck's plug-in preset menu provides common profile settings and loading these will help orient you to the many options that this meter provides. I find the external reference meter extremely useful to provide a real-time reference level of another track in my session. True-peak levels have also become increasingly important for any audio that will be encoded into a compressed format, and MasterCheck provides confidence that your audio will meet specific distribution requirements. Despite the complexity and thoroughness of this plug-in, the manual is brief and easily digestible. I think the MasterCheck plug-in by itself is worth the price of this bundle.
The most involved and complex plug-in of the Modern Mastering Bundle is called Visualizer. This plug-in, designed for comprehensive audio analysis, is comprised of eight different visual analysis displays. These tools include a variety of level meters, frequency spectrum analyzers, spectrogram displays, vector scopes, and phase correlation meters. Each meter display may be individually turned on or off, plus each display has its own preferences settings for behavior and look. Further, any display may be "soloed" and takes over the entire plug-in window to show more of that view. For instance, the user can select a familiar looking spectrum analyzer and customize its behavior and appearance while the vectorscope displays either a familiar Lissajous or polar plot while the level meter displays LKFS, RMS, FS, or various mid/side information. The in-depth spectrogram meters display frequency and level against time, with mouse-over detail readouts, while the phase correlation meters can show simple stereo phase correlation or phase correlation displayed over the entire frequency range. In my case, I set the K meter to show green bars up to K-12, yellow bars from -12 to -8 and red bars above -8 dBFS. Those settings make it very easy to get a sense of the level without having to read specific numbers on the meter scale. Similarly, I could adjust the response and fallback times of the meter in either horizontal or vertical display modes. Each of the eight displays has a similar depth of control and really must be explored to develop a set of meters that is comfortable for a given production task.
As with the MasterCheck plug-in, the Visualizer provides a comparison button to quickly compare the current audio to a reference track, again by using NUGEN's Send plug-in on the reference audio track. The comprehensive and concise manual for the Visualizer provides an informative section that explores the technical background and applications of FFT analysis, which is the foundation of the Visualizer plug-in. Understanding FFT analysis is certainly not required to use the MasterCheck meter, but it may help in understanding some of the meter's geekier preference settings.
Overall, the Modern Mastering Bundle provides a suite of professional tools for anyone who requires an understanding and control over master levels for audio production for music mastering and distribution, podcast or audiobook production, game audio, or mixing for film and TV. Some plug-ins, like the ISL in the NUGEN Modern Mastering Bundle, provide stereo-only operation while the complete ISL provides multi-channel metering for 5.1 or 7.1 surround production.