Text-to-Audio Workflow

This guide walks you through the Text-to-Audio (T2A) workflow: a ComfyUI workflow that generates audio from a text prompt using LTX-2.5 in audio-only mode. No video input or output is involved — the model generates audio directly from your description.

The workflow uses LTXVAudioOnlyModel to disable the model’s video pathway, running only the audio stream of the joint audio-video transformer. This produces audio with zero dependence on visual content, while reusing the same checkpoint and text encoder as standard video generation.

When to Use

Text-to-Audio is the right workflow when you want to generate audio from a text description without any video. If you need audio synchronized to video, use the standard Text-to-Video workflow instead, which generates audio and video jointly.

Prerequisites

This guide assumes you’re familiar with ComfyUI basics. If you’re new to LTX in ComfyUI, start with the ComfyUI setup guide.

Model Files

Step-by-Step

1. Download and Load the Workflow

Download the Text-to-Audio workflow JSON from our GitHub repository and drag it into ComfyUI.

2. Install Custom Nodes and Download Models

This workflow requires the ComfyUI-LTXVideo custom node package. Open the Workflow Overview panel (right sidebar) to check for missing nodes or model files.

3. Write Your Prompt

Find the positive prompt node and describe the audio you want — the sound, speech, or audio scene. To expand a short prompt, enable the Gemma 4 prompt enhancer (LTXVGemmaEnhancePrompt); the negative prompt is not enhanced.

Example prompt:

A woman saying: “Oh, what a lovely day we are having!“

4. Set Duration

Set the number of frames for your desired audio length; the audio latent length is determined by the frame count and frame rate (audio duration = num-frames ÷ frame-rate). The frame count follows the 1 + a multiple of 8 pattern, the same convention as video.

5. Generate

Click Run. The 8-step distilled schedule produces audio in seconds.

6. Preview

The PreviewAudio node at the end of the workflow plays the generated audio directly in ComfyUI.

How the Pipeline Works

LTX is a joint audio-video transformer that processes both modalities in a single model. The T2A workflow puts it into audio-only mode with LTXVAudioOnlyModel, which disables the video stream and cross-modal attention so only the audio pathway runs:

1. Load model — The distilled LTX-2.5 transformer is loaded, then LTXVAudioOnlyModel disables the video stream and audio↔video cross-attention.
2. Encode prompt — Your text is encoded with the Gemma 4 text encoder (the same encoder used for video), with an optional Gemma 4 enhancer to expand short prompts.
3. Prepare latents — An empty audio latent is created for the target duration, concatenated with a minimal dummy video latent that the model never processes in audio-only mode.
4. Sample — The audio is denoised on the distilled 8-step schedule at CFG 1.
5. Decode — The audio latent is separated from the dummy video and decoded through the audio VAE.

Tips & Troubleshooting

• Keep cfg near 1. The distilled model bakes guidance into distillation; explore samplers and cfg but stay near 1.
• Audio length. Adjust the frame count to control duration.

Technical Notes

• LTX is a single joint audio-video transformer that splits its input into [video, audio] streams; LTXVAudioOnlyModel disables the video stream rather than using a separate audio model.
• A dummy video latent is concatenated with the audio latent via LTXVConcatAVLatent before sampling; in audio-only mode those tokens are never attended to.
• After sampling, LTXVSeparateAVLatent splits the output and only the audio latent is decoded, via LTXVAudioVAEDecode.
• The audio VAE (ltx-2.5-audio-vae-bf16.safetensors) is loaded as a separate file via VAELoader; no video VAE is loaded in audio-only mode.