Heavily modified LTX-2 Official i2v workflow with Kijai's Mel-Band RoFormer Audio model for using an external MP3 to add audio. This post shows how well (or not so well) LTX-2 handles realistic and non-realistic i2v lip sync for music vocals.

Link to workflow on my github:

[https://github.com/RageCat73/RCWorkflows/blob/main/011326-LTX2-AudioSync-i2v-WIP.json](https://github.com/RageCat73/RCWorkflows/blob/main/011326-LTX2-AudioSync-i2v-WIP.json)

Downloads for exact models and loras used are in a markdown note INSIDE the workflow and also below. I did add notes inside the workflow for how to use it. I strongly recommend updating ComfyUI to v0.9.1 (latest stable) since it seems to have way better memory management.

Some features of this workflow:

* Has a Load audio and "trim" audio to set start point and duration. You can manually input frames or hook up a "math" node that will calculate frames based on audio duration.
* Resize image node dimensions will be the dimensions of the video
* Fast Groups RG3 bypass node will allow you to disable the upscale group so do a low-res preview of your prompt and seed before doing a full upscale.
* The VAE decode has a "tile" node to help with speed and memory issues
* Has a node for the camera static lora and a lora loader for the "detail" lora on the upscale chain.
* The Load model should be friendly for the other LTX models with minimal modifications.

I used a lot of "Set Node" and "Get Nodes" to clean up the workflow spaghetti - if you don't know what those are, I would google them because they are extremely useful. They are part of KJnodes.

I'll try to respond to questions, but please be patient if I don't get back to you quickly. 

I think this workflow will be ok for lower VRAM/System RAM users as long as you do lower resolutions for longer videos or higher resolutions on shorter videos. It's all a trade off.

Models and Lora List

\*checkpoints\*\*

\- \[ltx-2-19b-dev-fp8.safetensors\]

[https://huggingface.co/Lightricks/LTX-2/resolve/main/ltx-2-19b-dev-fp8.safetensors](https://huggingface.co/Lightricks/LTX-2/resolve/main/ltx-2-19b-dev-fp8.safetensors)

\*\*text\_encoders - Quantized Gemma

\- \[gemma\_3\_12B\_it\_fp8\_e4m3fn.safetensors\]

[https://huggingface.co/GitMylo/LTX-2-comfy\_gemma\_fp8\_e4m3fn/resolve/main/gemma\_3\_12B\_it\_fp8\_e4m3fn.safetensors?download=true](https://huggingface.co/GitMylo/LTX-2-comfy_gemma_fp8_e4m3fn/resolve/main/gemma_3_12B_it_fp8_e4m3fn.safetensors?download=true)

\*\*loras\*\*

\- \[LTX-2-19b-LoRA-Camera-Control-Static\]

[https://huggingface.co/Lightricks/LTX-2-19b-LoRA-Camera-Control-Static/resolve/main/ltx-2-19b-lora-camera-control-static.safetensors?download=true](https://huggingface.co/Lightricks/LTX-2-19b-LoRA-Camera-Control-Static/resolve/main/ltx-2-19b-lora-camera-control-static.safetensors?download=true)

\- \[ltx-2-19b-distilled-lora-384.safetensors\]

[https://huggingface.co/Lightricks/LTX-2/resolve/main/ltx-2-19b-distilled-lora-384.safetensors](https://huggingface.co/Lightricks/LTX-2/resolve/main/ltx-2-19b-distilled-lora-384.safetensors)

\*\*latent\_upscale\_models\*\*

\- \[ltx-2-spatial-upscaler-x2-1.0.safetensors\]

[https://huggingface.co/Lightricks/LTX-2/resolve/main/ltx-2-spatial-upscaler-x2-1.0.safetensors](https://huggingface.co/Lightricks/LTX-2/resolve/main/ltx-2-spatial-upscaler-x2-1.0.safetensors)

Mel-Band RoFormer Model - For Audio

\- \[MelBandRoformer\_fp32.safetensors\]

[https://huggingface.co/Kijai/MelBandRoFormer\_comfy/resolve/main/MelBandRoformer\_fp32.safetensors?download=true](https://huggingface.co/Kijai/MelBandRoFormer_comfy/resolve/main/MelBandRoformer_fp32.safetensors?download=true)

  
If you want an Audio Sync i2v workflow for the distilled model, you can check out my other post or just modify this model to use the distilled by changing the steps to 8 and sampler to LCM.

  
This is kind of a follow-up to my other post:

[https://www.reddit.com/r/StableDiffusion/comments/1q6ythj/ltx2\_audio\_input\_and\_i2v\_video\_4x\_20\_sec\_clips/?utm\_source=share&utm\_medium=web3x&utm\_name=web3xcss&utm\_term=1&utm\_content=share\_button](https://www.reddit.com/r/StableDiffusion/comments/1q6ythj/ltx2_audio_input_and_i2v_video_4x_20_sec_clips/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button)

LTX-2 Audio Synced to added MP3 i2v - 6 examples 3 realistic 3 animated - Non Distilled - 20s clips stitched together (Music: Dido's "Thank You")