# Default CFG Scales for Video and Audio in LTX-2: Complete Technical Reference

> Discover LTX-2 default CFG scales for video and audio generation. Learn the technical specifics for optimizing your creative projects with Lightricks.

- Repository: [Lightricks/LTX-2](https://github.com/Lightricks/LTX-2)
- Tags: api-reference
- Published: 2026-06-21

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**LTX-2 uses a default CFG scale of 3.0 for video generation and 7.0 for audio generation**, defined in the pipeline constants and exposed via the command-line interface.

LTX-2, Lightricks' open-source video generation model, relies on **classifier-free guidance (CFG)** to control how closely outputs follow text prompts. The **default CFG scales for video and audio in LTX-2** are hardcoded in the pipeline utilities and propagate through the argument parser to provide out-of-the-box generation behavior. These values determine the strength of guidance applied during the diffusion process for each modality.

## Default CFG Scale Values in LTX-2

The repository defines distinct defaults for video and audio modalities to account for their different generation characteristics.

- **Video**: **3.0** (defined at line 40)
- **Audio**: **7.0** (defined at line 50)

These values represent the baseline guidance strength before any user overrides are applied.

## Where Default CFG Scales Are Defined in the Source Code

### Pipeline Constants ([`constants.py`](https://github.com/Lightricks/LTX-2/blob/main/constants.py))

The canonical values reside in [`packages/ltx-pipelines/src/ltx_pipelines/utils/constants.py`](https://github.com/Lightricks/LTX-2/blob/main/packages/ltx-pipelines/src/ltx_pipelines/utils/constants.py). This file contains the `VIDEO_DEFAULT_CFG_SCALE` and `AUDIO_DEFAULT_CFG_SCALE` constants, which initialize the `video_guider.cfg_scale` and `audio_guider.cfg_scale` attributes respectively.

### Command-Line Argument Parser ([`args.py`](https://github.com/Lightricks/LTX-2/blob/main/args.py))

The [`packages/ltx-pipelines/src/ltx_pipelines/utils/args.py`](https://github.com/Lightricks/LTX-2/blob/main/packages/ltx-pipelines/src/ltx_pipelines/utils/args.py) file constructs the CLI parser by referencing these guider instances. When `default_1_stage_arg_parser()` builds the argument list, it pulls the current values from `video_guider.cfg_scale` (3.0) and `audio_guider.cfg_scale` (7.0) as the defaults for the `--video-cfg-guidance-scale` and `--audio-cfg-guidance-scale` parameters.

## How to Check Current CFG Scale Defaults

You can inspect the active defaults programmatically using the argument parser:

```python
from ltx_pipelines.utils.args import default_1_stage_arg_parser
from ltx_pipelines.utils.constants import VIDEO_DEFAULT_CFG_SCALE, AUDIO_DEFAULT_CFG_SCALE

parser = default_1_stage_arg_parser()
args = parser.parse_args([])  # No CLI overrides

print(f"Video CFG scale: {args.video_cfg_guidance_scale}")   # Output: 3.0

print(f"Audio CFG scale: {args.audio_cfg_guidance_scale}")   # Output: 7.0

```

## How to Override Default CFG Scales

Override these values at runtime using command-line flags:

```bash
python -m ltx_pipelines.ti2vid_two_stages \
    --reference-video input.mp4 \
    --video-cfg-guidance-scale 5.0 \
    --audio-cfg-guidance-scale 9.0

```

The values `5.0` and `9.0` replace the defaults (3.0 and 7.0) for this specific generation run.

## Summary

- **Video default CFG scale**: **3.0**, optimized for temporal consistency and smooth motion
- **Audio default CFG scale**: **7.0**, providing stronger prompt adherence for sound generation
- **Source location**: [`packages/ltx-pipelines/src/ltx_pipelines/utils/constants.py`](https://github.com/Lightricks/LTX-2/blob/main/packages/ltx-pipelines/src/ltx_pipelines/utils/constants.py) (lines 40 and 50)
- **CLI exposure**: [`packages/ltx-pipelines/src/ltx_pipelines/utils/args.py`](https://github.com/Lightricks/LTX-2/blob/main/packages/ltx-pipelines/src/ltx_pipelines/utils/args.py) via `--video-cfg-guidance-scale` and `--audio-cfg-guidance-scale`
- **Modification**: Pass explicit values via command-line arguments or edit the constants file directly

## Frequently Asked Questions

### What is the default CFG scale for video in LTX-2?

The default CFG scale for video generation in LTX-2 is **3.0**, defined in the `VIDEO_DEFAULT_CFG_SCALE` constant within [`packages/ltx-pipelines/src/ltx_pipelines/utils/constants.py`](https://github.com/Lightricks/LTX-2/blob/main/packages/ltx-pipelines/src/ltx_pipelines/utils/constants.py). This lower value helps maintain natural motion and temporal coherence in generated video sequences.

### What is the default CFG scale for audio in LTX-2?

The default CFG scale for audio generation in LTX-2 is **7.0**, specified in the `AUDIO_DEFAULT_CFG_SCALE` constant in the same constants file. This higher value ensures stronger adherence to text prompts, which is necessary for generating audio that accurately matches descriptive content.

### How do I change the CFG scale in LTX-2?

You can change the CFG scale by passing the `--video-cfg-guidance-scale` or `--audio-cfg-guidance-scale` arguments when running pipeline scripts such as [`ti2vid_two_stages.py`](https://github.com/Lightricks/LTX-2/blob/main/ti2vid_two_stages.py). For example, use `--video-cfg-guidance-scale 5.0` to increase video guidance strength from the default 3.0 to 5.0 for a specific generation task.

### Why are the video and audio CFG scales different?

The video and audio CFG scales differ because audio generation typically requires stronger guidance (7.0) to produce coherent, text-aligned sounds, while video generation uses a lower value (3.0) to prioritize smoother motion and temporal consistency over strict literal interpretation of prompts. This separation allows each modality to optimize for its specific perceptual requirements.