Mirelo released SFX 1.6 on May 19, shifting its video-to-audio model from one-shot generation to iterative editing. The official release notes introduce audio extension, inpainting, seamless loops, and longer generation windows, letting creators revise a generated track instead of regenerating it from scratch every time.
What you can do with this in a video edit
The new editing primitives map cleanly onto a working video timeline. Generate a base ambient bed for a 10-second shot, then extend it to cover the full sequence without a hard loop seam. If a footstep lands wrong against an explosion cue, inpaint just that region rather than re-rolling the whole take. The DaVinci Resolve Studio plugin keeps the audio in the same project that holds your edit, and the developer API at $0.007/sec on fal.ai lets pipelines call SFX-1.6 inside ComfyUI or n8n workflows.
Why it matters
AI video generation has outpaced AI audio for two years, so most Sora, Veo, and Kling clips ship silent or with a placeholder track. Mirelo, which raised $41M from Index and a16z in December 2025 to close that gap, is now closing the iteration loop too. The earlier SFX-1.5 release could produce a synced track, but a track you cannot edit is a track you cannot use in client work. Inpainting and extension move the model from demo toy to a tool a sound editor can actually finish a delivery with.
Key details
SFX 1.6 is a paired video-to-audio and video-to-video model. Input is a clip plus an optional text prompt; output is a synced sound track aligned to motion, emotion, and pacing in the source video. The model is positioned by Mirelo as commercial-use and is offered as a partner model on fal.ai. Audio extension supports stitching past the original 10-second cap, and inpainting accepts a time range plus an optional re-prompt for the patched region.
What to do next
If you cut in DaVinci Resolve, install the Mirelo plugin and run SFX 1.6 against a silent AI-generated clip you have sitting in a project right now. If you build pipelines, swap an MMAudio call for the fal.ai endpoint and compare output on a 30-second timeline that needs an extension splice. The iterative-editing model only pays off once you stop treating audio generation as a one-shot step.
