aufklarer / Stable-Audio-3-DiT-Medium-MLX-8bit

Stable-Audio-3-DiT-Medium-MLX-8bit

• speech-swift — Apple SDK
• soniqo.audio — website
• blog — blog

MLX port of Stability AI Stable Audio 3 (optimized) . Latent-diffusion text-to-audio with mask-based inpainting and continuation, with the DiT denoiser quantized to INT8 for Apple Silicon.

What's in this bundle

Codec stays FP32 because the SAME differential attention catastrophically cancels in FP16 (per Stability's own MLX runtime). T5Gemma stays FP16 — it's small relative to the DiT and quantization gives no speed-up on the short prompt encode pass.

Files

Capabilities

• Text-to-audio generation (music + SFX depending on DiT specialisation)
• Inpainting / region editing via masked latent diffusion
• Audio continuation from a short prompt clip
• Variable-length generation up to several minutes

The DiT-Small-Music-* variant is music-specialised; DiT-Small-SFX-* is sound-effects specialised; DiT-Medium-* is the higher-quality general model.

Usage

This bundle is the quantized weights only — inference uses Stability AI's official pure-MLX runtime at stable-audio-3/optimized/mlx . At load time, each (base.weight, base.scales, base.biases) triplet is dequantized via mlx.core.dequantize back to FP16; codec and T5Gemma load as-is.

from huggingface_hub import snapshot_download
import mlx.core as mx

bundle = snapshot_download("aufklarer/Stable-Audio-3-DiT-Medium-MLX-8bit")

def load_component(comp_dir):
    w = dict(mx.load(f"{comp_dir}/model.safetensors"))
    bases = {k[:-7] for k in w if k.endswith(".scales")
              if f"{k[:-7]}.weight" in w and f"{k[:-7]}.biases" in w}
    out = {}
    for k, v in w.items():
        if k.endswith((".scales", ".biases")) and k.rsplit(".", 1)[0] in bases:
            continue
        if k.endswith(".weight") and k[:-7] in bases:
            base = k[:-7]
            out[k] = mx.dequantize(w[f"{base}.weight"], w[f"{base}.scales"],
                                   w[f"{base}.biases"], group_size=64, bits=8)
        else:
            out[k] = v
    return out

Plug the rehydrated dict into the matching model class from stable-audio-3/optimized/mlx/models/defs/ .

Source

• Upstream weights: stabilityai/stable-audio-3-optimized (Stability AI Community License)
• Text encoder lineage: google/t5gemma-b-b-ul2 (Gemma Terms of Use)
• Paper: Stable Audio 3 — Stability AI

License

Stability AI Community License — free for non-commercial research and for commercial use up to the revenue threshold defined by Stability AI; see the license text . T5Gemma component additionally inherits the Gemma Terms of Use .