A mix is not truly finished until it is properly exported and delivered. This final, critical step is where the hours of careful work are translated into a professional deliverable that can be used by broadcasters, streaming platforms, and distributors. A small error in this stage can lead to costly delays or, worse, a compromised final product. This guide will provide a deep, technical breakdown of the final export process, covering everything from loudness compliance to the critical art of creating a high-quality stereo downmix.

1. Final Mix Preparation and Quality Control

Before you hit the export button, a final quality control (QC) pass is essential. This is a moment to step back and listen to your entire mix from start to finish, not just for creative decisions but for technical errors that may have slipped through the cracks. The most critical technical check is **loudness compliance**.

Loudness Compliance and Metering

The days of "mixing to peak" are long gone. The industry standard is now to mix to a specific loudness target, measured in **Loudness Units Full Scale (LUFS)**. For most streaming platforms and broadcast networks, this target is between **-24 LUFS** and **-27 LUFS**. Your final QC pass should be done with a high-quality loudness meter, such as `iZotope Insight` or `Waves WLM Plus`. You must check the **integrated loudness** of the entire mix, as well as the **short-term loudness** and **true peak** to ensure your mix is compliant with the required specification. It is a best practice to ensure that your mix’s true peak does not exceed **-2 dBTP** to prevent clipping on consumer playback devices.

During this final pass, you should also check for any technical errors, such as clicks, pops, or unintended silence. A final listening pass in a calibrated monitoring environment is the best way to catch these subtle issues. This is also the time to make sure that the dialogue remains clear and intelligible, and that the music and sound effects are not overpowering the narrative.

2. The Final Deliverables: Exporting the Master

The final mix is typically delivered as two separate files: the full multichannel master and a stereo downmix. These two files are the foundation of your final delivery package and are essential for international distribution and broadcast.

The Multichannel Master

The multichannel master is the final, full-resolution file of your mix. It is typically a **5.1 Broadcast Wave File (BWF)**. The file format is crucial, as BWF files contain embedded metadata, including timecode, which allows the file to be easily synced in any professional post-production environment. A common mistake is to deliver a standard WAV file, which lacks this critical metadata and can cause sync issues. The multichannel master should be exported at the same sample rate and bit depth as your session, typically **48 kHz** and **24-bit**.

The Stereo Downmix

A **stereo downmix** is a stereo version of your multichannel mix. It is not as simple as summing the left and right channels. A proper downmix is a carefully balanced blend of all five full-range channels. The primary purpose of a downmix is to ensure that a mix created in a multichannel environment sounds correct on a consumer stereo system, such as a television or a laptop. A professional mixer will use a specific downmix matrix to create a stereo downmix that is balanced, coherent, and free of phasing issues.

3. The Downmix Matrix: A Technical Breakdown

The **downmix matrix** is the technical formula used to create a stereo downmix from a multichannel mix. The most common downmix matrix is the **Lo/Ro (Left-only/Right-only)** downmix, which sums the 5.1 channels into a stereo pair using the following rules:

L_out = L + C(-3 dB) + Ls(-3 dB)
R_out = R + C(-3 dB) + Rs(-3 dB)

The **center channel (C)** is attenuated by **3 dB** to prevent the dialogue from being too loud on a stereo system, as the dialogue is typically panned to the center channel in a 5.1 mix. The **surround channels (Ls and Rs)** are also attenuated by **3 dB** to maintain the integrity of the surround soundstage. The **LFE channel** is typically ignored in a stereo downmix. This is because the LFE channel is a dedicated channel for low-frequency effects and is not intended to be heard on a stereo system. A common mistake is to include the LFE channel in the downmix, which can result in a muddy, undefined mix. Many DAWs and plugins automate this process, but understanding the underlying technical principles is crucial for a professional workflow.

4. Metadata and Naming Conventions

Once all files are exported, they must be properly labeled and organized. This is a critical step that ensures the final deliverables are easily identifiable and can be used by a wide range of professionals. Adhere to a strict naming convention that includes the project name, mix version, stem, format, and date. For example:

[ProjectName]_[MixVersion]_51_DM_STEREO_YYYYMMDD.wav
[ProjectName]_[MixVersion]_51_DM_STEREO_No_MX_YYYYMMDD.wav
[ProjectName]_[MixVersion]_51_DX_YYYYMMDD.wav

This comprehensive naming convention ensures that your final deliverables are easy to find, track, and manage. It is a simple step that can save you a lot of time and hassle down the road. This is the final step in a professional post-production workflow. By adhering to these standards, you can ensure that your hard work is translated into a final product that is technically flawless and ready for a global audience.

Conclusion

The final export and delivery of a mix is a critical part of the post-production workflow. By adhering to a professional workflow, including a final QC pass, a careful downmix, and a strict naming convention, you ensure that your work is ready for a wide range of distribution channels. This attention to detail is what separates a professional mix from an amateur one. Now that you have a firm grasp of the entire process, from setting up the session to final delivery, you are ready to take your skills to the next level.