Video generation models have long shipped with an awkward default: silence. Voiceover, sound effects and ambient audio get bolted on later with TTS tools and editors, and lip-sync is manual work. On October 4, Kandinsky Lab released the paper "Kandinsky 6.0 Video: Foundation Models for Synchronized Video and Audio Generation" (arXiv:2610.05608), and two days later open-sourced the weights, code and diffusers integration under the MIT license — turning synchronized audio-video generation from a closed-flagship feature into a public capability.

Two sizes, one pass

The release is a pair of models: Lite at 3B parameters and Pro at 29B. Both directly output 5-second clips with synchronized 44kHz audio and lip-sync, in text-to-audio-video (T2AV) and image-to-audio-video modes; a separate 1.4B super-resolution diffusion model upscales results to Full-HD (1920×1080). The paper lists more than 80 authors.

Dual-stream CrossDiT

The architectural story is the dual-stream design: a pretrained video stream building on Kandinsky 5.0's video capabilities, plus an audio stream trained from scratch — first on large-scale audio-only corpora, then jointly with the video stream on paired audio-video data. Bidirectional cross-attention aligns the two streams in time and semantics while preserving unimodal fidelity. Pretraining is followed by supervised fine-tuning, RL-based post-training and distillation. Per the official numbers, RL post-training cut Pro's speech word error rate (WER) by 47% — the hardest number in this release.

On the team's own VABench benchmark, Pro beats LTX 2.5 and the Lite sibling on speech quality, audio aesthetics, AV alignment, lip-sync and visual realism; in human evaluation Pro clearly outperforms Kandinsky 5.0 Pro and is preferred over LTX 2.5 on visual quality, motion realism and artifact reduction, with a statistically significant edge in speech quality. These are vendor-run evaluations — treat them as official claims, not independent ones.

Consumer GPUs and day-one ecosystem

The README's measured numbers are refreshingly honest: on the non-distilled Lite, a 5-second clip takes about 437 seconds on an RTX 4090 and 239 seconds on an H100; Pro at Full-HD takes about 402 seconds on an H100 and roughly 854 seconds on an RTX 5090 with block offload. Slow, but consumer cards genuinely run it. On release day (October 6) the ecosystem landed together: ComfyUI node packs, vLLM-omni support and a Hugging Face Space demo went live the same day; the GitHub repo passed 120 stars within a day, and 8 model repos on Hugging Face already reference the paper.

So what

Synchronized audio-video generation has mostly been closed-flagship territory; open-source stacks assembled it from a video model plus TTS, with alignment and lip-sync as chronic pain points. Kandinsky 6.0 drops the full stack — two base models, super-resolution, distilled variants — under MIT at once, which is unusually friendly to local deployment and derivative work. The open question is length: 5 seconds is the current ceiling, and stretching synchronized generation to minutes is the next real fight.