As the final stage of post-production, mastering optimizes tracks and enhances overall sound quality. This is what spells the difference between a raw recording and a polished, professional release. It’s a pivotal part of music production and engineering, but it is complex to understand and navigate — in part because mastering strategies are always changing.
The latest developments nearly all relate to the proliferation of music streaming. Strategies that worked for the vinyl records and CDs of yesteryear may not deliver as strong of a listening experience when platforms like Spotify are involved. This is where targeted music mastering techniques must come into play, accounting for the nuances of streaming and the difficulties of working with multiple platforms.
There are numerous ways to optimize so that listeners enjoy an exceptional audio experience via streaming. We take a deep dive into these opportunities below, revealing how to master for Spotify, Apple Music and other streaming platforms.
Understanding the Requirements of Streaming Platforms
One of the biggest obstacles to optimizing sound quality via mastering is keeping up with so many different platform requirements. With physical media, streaming requirements were comparatively straightforward yet also allowed for greater freedom. Streaming platforms, however, set their own algorithms and specifications to keep up with. Essentials to understand when mastering music tracks for streaming include:
Loudness Normalization
Loudness normalization adjusts tracks automatically to ensure consistent volume levels across different songs and albums. This makes it a critical component of mastering for Spotify and other streaming solutions. It provides a more consistent listening experience rather than listeners encountering tracks that constantly seem too loud or too soft.
However, these benefits come with a few caveats. Depending on how tracks are mastered, they could suffer increased distortion or reduced clarity once they reach preferred streaming platforms. As a result, audio engineers need to be highly strategic in how they master tracks, as these choices could have unintended consequences. Balance is crucial, along with a tailored approach to accommodate differences in normalization between various platforms.
Codec Compression
Used to compress and store digital files, codecs aim to reduce bandwidth requirements and optimize file sizes without significantly compromising audio quality. These limit redundant data to promote faster streaming and efficient storage. This approach makes it possible to strike the ideal balance between compression and sound quality.
Codecs take many forms, with lossless solutions aiming to preserve the original sound quality. This is by far the preferred strategy for audiophiles, but it may result in larger file sizes. Lossy codecs are more likely to prompt some changes to audio quality, though these are often quite modest. More common with streaming, this approach is preferable when priorities include file size and bandwidth.
Metadata and Delivery Specifications
Information can be embedded within audio files to help identify and organize various tracks. Known as metadata, this helps guide listeners to various artists, albums or songs — and is therefore a key part of the distribution process. Streaming platforms maintain detailed guidelines that outline what should be included to help listeners.
Other guidance may relate to file delivery. Many platforms require WAV files or specific sample rates (often 44.1 kHz). Higher sample rates are associated with higher-quality audio. Bit depth matters, too, revealing the number of bits representing various audio samples. The preferred bit depth is typically 16-bit, but some platforms may accommodate 24-bit samples.
Once these details have been covered, it’s time to deliver the desired files. This may involve submitting tracks via music distribution services, although it is sometimes possible to submit tracks directly to streaming platforms.
Mastering Techniques for Streaming Platforms
When mastering for streaming platforms, it is essential to consider the unique requirements and limitations of each. While these far-reaching considerations can complicate the mastering process, they can also provide opportunities to reach and appeal to specific types of listeners. These audio mastering tips and techniques should help:
H3: Setting Appropriate Loudness Levels
When determining preferred loudness, keep in mind that different streaming platforms establish different standards (as discussed in more detail below). It is important to understand these varying standards, which may be expressed in loudness units relative to full scale (LUFS). The concept of True Peak is also noteworthy; this highlights the maximum point that audio can reach without suffering distortion.
Typically, loudness is determined via dedicated loudness meters, which should highlight both momentary and integrated LUFS. The overall loudness (expressed via integrated LUFS) may need to be adjusted to align with each platform’s target loudness levels.
Optimizing Frequency Balance
Revealing how frequencies are distributed within tracks, frequency balance can deliver a harmonious sound. There are many ways to optimize frequency balance, but techniques such as equalization (EQ) are often used to boost or cut various frequencies. Spectrum analyzers can prove valuable from a visualization perspective, helping producers or engineers identify problem areas that might otherwise be difficult to pinpoint. The ultimate goal is to achieve an equal distribution of energy across various tones.
Managing Dynamics and Compression
Dynamic range should remain a priority throughout the mastering process, as overly compressed audio may have a dull or even lifeless effect. Still, this must be tailored in the context of streaming-based loudness concerns. Metering plug-ins can be useful for monitoring dynamic range, offering real-time feedback to aid the ear in identifying that critical sweet spot between engaging sounds and optimal clarity.
When it comes to striking that balance between dynamic range and compression, NPR audio engineer Andy Huether provides an important reminder: “Compression lowers the highest level portions of a signal, reducing the overall dynamic range.”
Handling Stereo Imaging
Stereo imaging reveals how various track elements are placed within a broad stereo field. The stereo field’s center helps to maintain a strong focus. Width promotes a sense of depth, offering greater immersion. Different sounds could potentially be placed in left and right channels, although a centered approach can yield a more cohesive effect.
Despite these far-reaching stereo imaging opportunities, it remains essential to check for mono compatibility, as this ensures that tracks still sound good when various streaming platforms or devices are involved.
Platform-Specific Considerations
Much of the complication of mastering for streaming platforms involves the sheer variety of platforms and different requirements these may entail. This is where distribution concerns enter the picture — and in some cases, it may be necessary to compromise select audio priorities for the sake of monetization and to ensure the right audience is reached. Numerous complications accompany mastering levels for streaming, but understanding a few top platforms can help:
Spotify
Spotify aims to provide a uniform listening experience via loudness normalization. The platform recommends targeting the loudness level at -14dB integrated LUFS or, at least, remaining below -2dB TP (True Peak) to limit distortion. Spotify loudness standards can be frustrating to some producers who perceive the platform’s approach as aggressive — but with 640 million users, this remains a compromise that many producers and engineers are willing to make.
Apple Music
Having adopted -16 LUFS as its standard, Apple Music has become the preferred platform among some audiophiles, as ALAC (Apple Lossless Audio Codec) makes it possible to enjoy the elite sound quality of lossless tracks. Many regard mastering for Apple Music as a middle ground of sorts that offers a slightly less aggressive approach to loudness but a larger audience than most alternative platforms.
Other Platforms
Spotify and Apple Music attract the bulk of the attention, but these represent just two of many streaming platforms worth considering when navigating the mastering process. Optimal mastering may look different when dealing with alternative options such as SoundCloud. Additionally, TIDAL is favored for its high-fidelity opportunities.
Tools and Software for Mastering
Ear training plays a central role in preparing for mastering success, but this process can also be supported by a wide range of tools and technologies. These make it easier to achieve preferred streaming audio quality while still accommodating the often strict standards imposed by today’s top platforms.
Essential Plugins for Mastering
The right plugin can transform the mastering process, offering precise control over the nuances of audio quality. A range of compelling plugins are available, which may make choosing the right option for any given track overwhelming. Many producers and audio engineers stand by these favorites:
- iZotope Ozone 10
- IK Multimedia’s T-RacksS 5
- Softube Weiss DS1-MK3
- Signum Audio BUTE Loudness Suite
When choosing a plugin, be mindful of how various options might accommodate streaming platforms. For example, Signum Audio BUTE Loudness Suite is an excellent option because it provides useful visual aids and makes it easy to select the target loudness. Another key consideration: whether a full suite is provided or whether plugins only handle a few select tasks.
Metering and Analysis Tools
From peak meters to stereo meters and especially loudness meters, many metering and analysis tools help fine-tune tracks and ensure that they meet specific standards. Ideally, these tools will provide in-depth yet easy-to-understand insights about volume levels, dynamic range and other essentials. The ultimate goal is to ensure that the music sounds impeccable regardless of the playback system. These can work in tandem with plugins to balance the technical foundation of mastering with creative goals.
Reference Tracks and A/B Comparison
Benchmarking can make a world of difference in the mastering process — providing a valuable point of comparison for ear training or to combat ear fatigue. A/B comparison may involve multiple versions of a given track, with the original mix referred to as the ‘A’ version and the newly mastered edition the ‘B’ label. These versions can be listened to back-to-back to uncover subtle but distinct differences in tonal balance or clarity.
In addition, reference tracks serve as a critical point of comparison. Pre-recorded and professionally mastered, these tracks aim to establish a high standard and can also help determine how cohesive entire albums feel. This remains a core consideration even in the era of streaming, as sonic consistency is still expected when listening to tracks via playlists.
Testing and Delivering Your Master
Masters must be carefully tested to ensure they translate well across a vast range of listening environments and devices. This process may involve extensive vetting, with the goal of quickly identifying issues that might not be evident in a more controlled environment. In the context of streaming, this can provide peace of mind regarding various loudness standards or other platform-specific concerns.
Testing Across Multiple Devices
Given the sheer range of playback systems available these days, it is more important than ever to test masters across numerous devices. This process should reveal how tracks function in various listening environments. Testing could potentially involve checking hardware configurations or even listening to tracks with and without headphones.
Reference tracks can once again prove valuable during the testing process, but ultimately, this comes down to a simple concern: Does the final product live up to the original vision for the track?
Preparing Final Files
File formats must be selected carefully; these can have a major impact on overall sound quality. WAV files are often favored due to their lossless nature, though FLAC is strongly recommended by Spotify. File naming and organization strategies matter, too, as this can limit confusion and even enhance collaboration. This could also prevent technical errors during the uploading process.
Future Trends in Mastering for Streaming
The art and science of mastering have evolved in response to streaming challenges and opportunities, but this transformation is just beginning. As streaming technology continues to advance, mastering will see considerable changes as well. Trends worth acknowledging include:
Spatial Audio and Dolby Atmos
Promising an immersive audio experience, Dolby Atmos moves beyond traditional surround sound to create a dynamic and exciting audio environment capable of enveloping the listener. This approach allows sound to move freely around listeners in all directions. The result? A heightened sense of realism and depth.
In the context of streaming, spatial audio has generated a great deal of interest among audiophiles, who crave a more immersive experience. Many hi-res options are already available. Specifically, TIDAL is known for promoting a spatial experience. Spotify is about to get in on the hi-res game, however — with CEO Daniel Ek having confirmed the development of an upper tier known as Spotify Super Premium, which will deliver higher-quality audio streaming.
AI and Automated Mastering
Artificial intelligence (AI) could hold significant implications for mixing and mastering, and while many producers and engineers have expressed concern about the rise of AI, others are excited about the supplemental opportunities it presents. Those who are hoping for streaming platforms to restrict AI, though, may be disappointed: Spotify, in particular, has made it clear that (with some exceptions) the use of AI in music will largely be tolerated.
Examples of AI’s value within the music production space abound. AI-based plugins offer intelligent equalization, with AI solutions even recognizing musical patterns and leveraging high-level analysis to apply dynamic range control. Intelligent noise reduction can remove unwanted hissing, while other tools can optimize loudness based on industry requirements and, increasingly, streaming necessities.
Automated mastering takes this a step further by relying on preset adjustments. This tends to involve a more rigid, heavy-handed approach and may present barriers to producers or audio engineers achieving their unique visions. When cost-effective, simplified mastering is desired, automation provides a realistic solution. As Rolling Stone points out, however, “AI is only as powerful as the minds that wield it.”
Explore Music Mastering Techniques With RMCAD
Discover cutting-edge opportunities in music mixing and mastering. At Rocky Mountain College of Art + Design, we provide the opportunity to delve into this exciting industry. RMCAD offers a range of ways to explore music mastering techniques, including an online music production degree program that delivers immersive virtual learning experiences and, for nearby students, access to the state-of-the-art Rocky Mountain Sound Lab (RMSL). Get in touch today to learn more.
