> ## Documentation Index > Fetch the complete documentation index at: https://hyperframes.heygen.com/llms.txt > Use this file to discover all available pages before exploring further. # Audio effects and mixing > Ask for a mix in symptoms rather than in filters — make music step out of the way of narration, clean a voice, and know which requests have no honest answer. The last chapter gave your video a voice. This one makes the voice and everything around it *listenable*. Audio work is where prompts go wrong in a specific way: it is tempting to name the machine. "Add a high-pass at 80 Hz with a Q of 0.7" is a real instruction, and it is worse than the request that produced it, because it commits you to a fix before anyone has established the problem. The mix is stored as effects on each track — filters, dynamics, character, space, and envelopes that move any of them over time — and the agent reaches into that toolbox for you. Your job is to describe the symptom accurately. ## Say what it sounds like, not what to add Every effect in the rack exists to answer a complaint. Name the complaint. ```text theme={null} The narration sounds muffled, like it's behind cardboard. Fix it. ``` ```text theme={null} The voice sounds amateur — clean it up but don't make it sound processed. ``` ```text theme={null} There's a hum under the interview audio the whole way through. ``` Each of those lands on a specific, small change: a cut at 250 Hz, the `voice-clean` chain, a high-pass under the voice. You do not have to know which — and if you name the wrong mechanism, you get the wrong mechanism applied confidently. This matters more than it does for picture work, because **you can hear a mix and the agent cannot**. A prompt describing a sound is evidence. A prompt naming a filter is a guess wearing evidence's clothes. ## The one request worth learning by name Music under narration is the single most common audio problem, and the reflex fix is wrong. Ducking the whole music track works and costs the music all of its presence for the entire voiceover — it goes limp for as long as anyone is talking. The voice does not need the whole spectrum, though. It needs the few bands it actually occupies. Taking only those out of the music is called a **carve**, and it keeps the low end and the top, so the bed is still music while the voice stays intelligible. Ask for it in those terms: ```text theme={null} Put the music under the narration properly — carve it so the voice stays clear without the track going limp. ``` ```text theme={null} The music is fighting the voiceover. Make room for the voice in the music rather than just turning the music down. ``` Two things are worth knowing so you can judge the result: * **It follows the speech.** Silence leaves the music alone; a loud passage pushes it to full depth. It is not a fixed dip held through every pause. * **It lives on the music**, and names the voices it makes room for. If someone tells you they carved the voice track, that is a bug rather than a taste decision. If it comes back and the music sounds *hollow* rather than simply quieter, say so in exactly that word — it means the depth is too high, and it is the one failure mode with an obvious sound: ```text theme={null} Too far — the music sounds notched now. Back it off. ``` ## Ask for levels before asking for more depth A carve cannot fix music that is simply louder than the voice. When narration is buried, the useful instruction is about **level**, not about spectrum: ```text theme={null} Check the actual loudness of the voiceover against the music before touching the carve — the voice may just be quieter than the bed. ``` Machine-generated speech commonly arrives far below a mastered music track. That gap is arithmetic, not taste, and no amount of carving closes it. Asking for the measurement first turns one round of guessing into a number. ## Group the things that belong together Five narration clips want one set of effects, one fader, and one mute — not five copies that drift apart as you edit. Say so: ```text theme={null} Group all the narration clips as one voiceover group, then carve the music against that group. ``` That phrasing is worth the extra clause. A carve pointed at individual clips has to list every one of them, and it stays right only until you add another — the sixth clip plays outside the carve's awareness and the music silently fails to duck under it. A carve pointed at a *group* picks up whatever is in the group at the time it runs. Use groups for sound effects too, when there are more than a couple. One place to turn all of them down is worth more than precise individual levels you will never revisit. ## Ask for movement when a static setting will not do Anything that should change over the video's length is an envelope, and you ask for it by describing the shape in time: ```text theme={null} Fade the music out over the last three seconds. ``` ```text theme={null} Bring the ambience up while the wide shot is on screen, then pull it back under the interview. ``` One caveat worth carrying: a few effects cannot move over time at all — the compressor, limiter, gate, bitcrush, and pitch shift are configured whole rather than knob-by-knob. If you ask for a compressor that tightens as a scene builds, the honest answer is a level stage moving in front of it instead. An agent that quietly writes an envelope on one of those has written something inert, so if a requested change does nothing audible, that is the first thing to suspect. ## Three requests with no honest answer Naming a gap is more useful than accepting the nearest preset and calling it the thing. **De-essing.** Sharp `s` sounds need a detector faster than anything in the toolbox. The nearest fix is a narrow cut in the 5–9 kHz range, swept to find where that particular voice spits. It is always on, so it costs a little air on every word. That trade is usually worth it — but ask for it knowing it is a trade: ```text theme={null} The s sounds are spitting. I know there's no real de-esser — put a narrow cut where this voice actually sibilates and tell me what it cost. ``` **Noise removal.** A gate closes the gaps between phrases; the hiss *underneath* the words is untouched by anything available. A source with audible hiss needs a better source, and an agent telling you so is being accurate rather than lazy. **Matching one voice to another.** There is no match-curve tool. Two takes can be brought closer by hand with an EQ, which is predictable in a way a derived curve would not be — but it is hand work, and worth asking for as such. ## Describe the whole mix once, at the end Individual fixes accumulate into something nobody has judged as a whole. One closing instruction is worth more than three more adjustments: ```text theme={null} Render an audio-only pass and check the mix end to end: voice clear through the loudest musical moment, effects where the action is, nothing surprising at the open, and the music finishing on purpose rather than at the file edge. ``` Audio problems are easier to notice when the picture is not competing for attention. Listening once without watching catches things twenty prompt rounds will not. *Next: [Design systems and brand](/prompting/design-systems) — pointing the agent at a source of brand truth instead of describing a vibe.* ## Related topics - [Audio effects implementation](/reference/audio-effects.md) - [Media and audio](/prompting/media-and-audio.md) - [Mix audio and apply effects](/studio/audio-effects.md)