Commercial Audio Post Production: Mixes, Stems, Cutdowns & Deliverables
What agency producers and creative teams should expect when a commercial moves from picture editorial into audio post—and why the :30 is usually only the beginning.
Commercial audio post production is a compressed version of a much larger post workflow. The runtime may be short, but the project can still require dialogue cleanup, voice-over editing, sound design, music editorial, client review, final mixing, cutdowns, stems and several destination-specific masters.
The mistake is assuming a short piece automatically means a simple piece. A thirty-second spot may contain fewer seconds than a documentary scene, but every second has to communicate efficiently. Dialogue, music, effects and brand elements all compete for limited space, and there is usually very little room for a weak transition or an unclear line.
What Happens During Commercial Audio Post?
Once picture is ready for sound, the audio-post team receives a reference movie, an AAF or other editorial turnover, production audio or voice-over, music and any existing effects. From there, the session is organized around three priorities: clarity, creative impact and delivery.
Dialogue and VO are cleaned and balanced first. Sound design then supports action, products, transitions and brand moments. Music may need edits or stems so the mix can make room for speech. The final mix brings those pieces together while keeping the destination in mind.
The Hero Mix Is Only One Deliverable
Agencies often think in terms of a hero spot, but audio post has to think in terms of versions. A :30 can become a :15, a :06, several social variants and a web version. Each cutdown changes the timing relationship between dialogue, music and effects.
That means a shorter version should not simply be exported from a longer mix. The mix needs to be checked against the new picture. A music hit may now be late. A transition may disappear. A VO line may need more room. The ending may need to feel finished even though half the runtime vanished.
Why Stems Matter
Stems are grouped audio elements delivered separately from the full mix. Common commercial stems include dialogue or VO, music and sound effects. They give the agency flexibility for later versions, localization, trafficking requirements or last-minute editorial changes.
Stems also make future revisions more practical. If a legal line changes, the entire soundtrack should not need to be rebuilt just to replace one sentence. Clean deliverables preserve options.
Broadcast, Web and Social Are Not the Same Destination
Different outlets may have different expectations for loudness, peaks, channel layout and file format. Even when a platform does not publish a formal broadcast-style specification, the mix still has to translate across phones, laptops, televisions and headphones.
A technically compliant mix can still fail creatively if the VO disappears on a phone speaker. A very aggressive social mix can also become exhausting on better playback systems. The job is to balance technical delivery with real-world listening.
What Agencies Should Confirm Before Final Mix
- Approved picture and runtime
- Final or near-final VO
- Music masters and available stems
- Required cutdowns and aspect-ratio variants
- Broadcast, web and social destinations
- Required stems and texted/textless versions
- Client review and approval path
Commercial audio post works best when those decisions are visible early. The mixer can then build the session around the actual delivery plan instead of discovering six new versions after everyone has already approved the “final” final mix.