After you are satisfied with your mix and you want to render a final mix-down, you use Cubase’s Export Audio Mixdown function [File (PC)/Cubase (Mac) > Export > Audio Mixdown. This function also lets you export a specific selection, a track containing effects, or a VSTi or ReWire track.

The Audio Mixdown function does not, however, export MIDI tracks for non-VSTi devices, such as ReWire devices, unless two conditions are met: the Real-Time Export option must be selected, and the external MIDI devices have to be configured using the VST Connections, as described in Chapter 10, “Using VST and MIDI Instruments.” The following steps assume that you have already configured your VST Connections accordingly and have previously converted your MIDI/instrument tracks into audio tracks, as described in Chapter 17, “Navigating MIDI Tracks.”

If you have enabled the Audio Track option in the Import into Project section, Cubase will create a new audio track. After the newly created track is in place, be sure to mute the source tracks for this new track (containing the audio mix-down).

If you have chosen not to import the audio rendering of your mix back into your project, you can proceed with your work as usual, continuing whatever work needs to be done, or save and close your project and start working on the mastering of your album, as discussed later in this chapter.

For the highest quality audio, which is what you want if you’re mixing for CD duplication, you can export your final mix in two lossless formats: WAV and AIFF. Both are standard formats and compatible with Mac and PC platforms. You can also use the Wave64 file format, which supports file sizes larger than 2 gigabytes.

If you’re mastering directly for digital distribution, you probably don’t want to go the lossless route, as this creates unwieldy file sizes. Instead, digital distribution favors smaller-sized, lower-quality compressed file formats. Cubase supports a variety of these download-friendly formats, including Microsoft Windows Media (PC only), MP3 (from MPEG 1 Layer 3), and Ogg Vorbis. Because these formats were developed with the Web in mind, they make it easy to stream or distribute content over a low-bandwidth system. As a result, a certain amount of audio data compression is applied to these file formats. The more you compress the files, the smaller they are, but this also directly affects sound quality—the higher the compression, the worse the sound quality. All these compression algorithms are lossy, meaning that they irretrievably remove sonic information from the original file when saving it into this new format, and by doing so they reduce sound quality as well.

By the way, don’t confuse data compression, which is used to compress the size of a file, with dynamic compression, which is used to control the dynamics of the audio signal. Compression of the dynamic range in audio material does not influence the size of the file, although it does decrease the audio quality. You will have a chance to experiment with compression settings for these digital audio file formats and will have to find a compromise that you are comfortable with in the end.

Now that your project is ready to be exported, it might be a good time to add information about who created the files. This information is called metadata, and you create it through Cubase’s Broadcast Wave properties function. The information you enter here is embedded in all the digital audio recordings/renderings you create in WAV format. Think of embedding this metadata as a way to label and keep track of your intellectual property; it lets everyone who uses your file know you are the owner.

Broadcast wave information contains three basic fields: a description, an author, and a time-stamped reference based on the timeline in your source Cubase project. This last bit of information can be useful when exchanging files with video editors, for example.

When you export a project using the File > Export > Audio Mixdown option, the Export Audio Mixdown dialog box offers an option to insert the broadcast wave chunk into the exported audio files. Checking this option will add the information you just added to the files. At that point, you can choose to edit this information further by clicking on the Edit button. This opens the Broadcast Wave Chunk dialog box, where you can change the information embedded into the audio file, as displayed in Figure 38.3.

Figure 38.3. The Broadcast Wave Chunk dialog box.

Mastering is the art of subtlety and involves adjusting a collection of final mixes so that they all sound coherent and cohesive when played sequentially. From the first mix you did two months ago to the one you just created this morning at 4:00 a.m., they should all have the same quality, sound level, and dynamic intensity. Think of mastering as the art of giving an album its soul.

When preparing an album, mastering is a must before pressing your master copy. The mastering process is used to reduce the aforementioned differences between various mixes by patching together every song in a one- to two-day span—listening to them in the order they will appear on your album and correcting the overall harmonic colors and dynamic range of your songs as necessary. You can also master a given recording for playback on different devices and media, such as compact disc versus online downloading.

It is also a good idea not to master your album with the same listening reference as you used for the recording and mixing process because your ears have probably grown accustomed to this sound and may no longer be as critical to some aspects or coloring of the music. Furthermore, if your monitoring system is adequate at best, you will probably benefit from a professional mastering facility rather than a home studio mixing environment because the better facilities provide the best all-around listening and processing equipment to truly isolate problems in the consistency between your songs, not to mention provide a fresh pair of ears listening to your project. This can add a whole new untapped dimension to your project, which is especially true if this is to be a commercially distributed album. No matter what the proponents of home-based recording might say, there will always be a difference in quality between a home studio filled with inexpensive equipment and low-quality components, and a quarter-million-dollar mastering facility in which every piece of equipment in the room is meant to optimize your sound.

When you use a professional mastering studio, you may need to provide your entire Cubase project or just your exported stereo WAV/AIFF files. Consult with the mastering engineer beforehand so you’ll know what they need—and maybe save yourself a little work, in the process.

If you don’t have the financial resources or you don’t feel the need for professional mastering because your project is for small and local distribution only, you can use Cubase’s mastering features to do the job yourself. Know, however, that there are no fixed recipes and no settings that can apply to every situation; rather, there are pointers that should help you get the most out of a mastering session.

That said, here is some advice worth considering:

If you’re mastering for compact disc or digital distribution, you need to add dithering to your master mix as a master insert effect. Put simply, dithering helps to reduce the potential for digital distortion in your recording, especially when you record in a 24- or 32-bit environment and then create a 16-bit master for CD or digital download.

Dithering works by adding a low level of random noise to your project, but in a way that masks actual noise. It’s virtually inaudible to the listener.

Why not just record in a 16-bit environment? It’s simple. Using 24-bit or higher resolution during the production process increases the potential dynamic range of your project, while reducing the possibility of any audible noise being introduced as a result of the digitization process itself. It also increases the signal-to-error ratio, which is the degree of rounding determined by the “resolution” or bit-depth. This error is more noticeable when signals are recorded at low levels or as they fade out to a lower level in reverb, for instance—especially if their levels get significantly boosted later in the mixing process.

As you saw earlier in this book, this signal-to-error ratio (in theory) is around 146 dB in a 24-bit recording and 194 dB in a 32-bit recording. Such a ratio suggests that when you record a sound using 32-bit resolution, your theoretical dynamic range is 194 dB, a signal-to-error ratio that is inaudible and negligible by any standards. Of course, in practice, you rarely get such impressive signal-to-noise ratios due to many noise-generating elements before and after the audio hardware’s converters, but the ratios are consistently more impressive when you are using higher bit rates.

All that said, when you transfer a stereo mix-down to a 16-bit medium, such as compact disc, you need to bring this precision down to 16-bit. There are two primary approaches you can employ to accomplish this reduction in bit depth: truncating and dithering.

Truncating simply cuts the least significant portion of the digital word that exceeds the 16-bit word length. This is not the recommended approach, as the eight digits you get rid of are often noticeable, especially in reverb trails or harmonics of instruments at low-level intensities. Cutting them off usually adds what is known as quantization error. The digital distortion of the original audio waveform produced by quantization error (in essence, a rounding error due to the word length not offering enough amplitude levels to accurately depict the waveform) sounds unnatural to human ears. You are probably familiar with some extreme examples of this, in the 8-bit audio used by certain children’s toys and vintage computers or game systems.

A good solution to this problem is to add a special kind of random noise to the sound when you need to bring down the resolution. This random noise is dither noise, and it randomly changes the last bit in a 16-bit word, creating a noise at –98 dB, which is pretty low.

Because dithering is—and should be—the last step in your mix-down process, it should only be added when you are exporting the final mix-down directly to a 16-bit sound file. Because of this, load the UV22HR dithering plug-in into the last insert slot of your output bus—number 8, which is a post-fader insert.

With this final option set, you are now ready to export your mix to an audio file.

It’s essential to make backup copies of your work during the course of a project. Not only does creating a backup prevent you from having to rerecord your material if you make mistakes and erase files, but it is also a good way to keep source material from being lost because of hard drive crashes. Another good reason to back up files as you are working with them is that you can always go back and change things later in an arrangement or create a new arrangement altogether by using the source material rather than the master two-track recording.

If these are not good enough reasons for you, consider this last piece of advice: When you are working on a project for someone else and charging studio time, it’s doubtful that your client will be impressed by your work if you lose some of their recordings!

There are many ways to do backups inside and out of Cubase:

Keeping in mind that computer crashes occur quite unexpectedly, and that disc failures are not as infrequent as you would want, making backup copies of your work makes sense—even after each working session. This way, you reduce the amount of time lost if something bad ever happens.

Reading the documentation provided with your DVD/CD burning and backup software to understand how it works and how you can retrieve information from backup discs and tapes might prove useful (especially in a crisis!), so take a little bit of time to familiarize yourself with these options.

When you want to use your Cubase files in other applications—to use a third-party mixing or mastering program, for example—you use Cubase’s OMF Export option. This option enables you to save your project in a platform- and application-friendly format.

OMF is friendly in the sense that this is a standard supported by more applications than the current .CPR or Cubase Project file might be. In other words, if you stay within Cubase, you won’t need to use the OMF export format, but if your project needs to be added to another application, such as Final Cut Pro or Avid, exporting to OMF format will save everyone lots of time because the volume and fade settings will be retained in the OMF version of your project, as well as the positions of the all the audio events within it. This implies that you won’t have to re-import and position all your audio content in another application.

Exported OMF files retain references to all audio files that are played in the project (including fade and edit files) and do not include unused audio files referenced in the Pool. They won’t contain any MIDI data either, so it’s important that you convert all your MIDI parts into audio events and render any tracks with inserts or send effects and include these “flattened” tracks when exporting the project to OMF. If your project contains a video file, the only thing that will be included in the OMF file are the start positions of video events. You will need to manually import video files later in the other OMF application.

At this point a single OMF file is created, which includes all the checked tracks. All the files are saved inside the destination folder.