VoxCPM2 (OpenBMB) is the studio-quality option: native 48 kHz output, zero-shot voice cloning, and — uniquely among VoiceStudio's engines — voice design: creating a synthetic voice from a text description ("young female, warm tone, British accent") with no reference audio at all.

• You want voice design without a reference clip.
• You want the highest output sample rate (48 kHz vs OmniVoice's 24 kHz).
• Your language is among its 30 supported languages: Arabic, Burmese, Chinese, Danish, Dutch, English, Finnish, French, German, Greek, Hebrew, Hindi, Indonesian, Italian, Japanese, Khmer, Korean, Lao, Malay, Norwegian, Polish, Portuguese, Russian, Spanish, Swahili, Swedish, Tagalog, Thai, Turkish, Vietnamese.

• Python ≥ 3.10, PyTorch ≥ 2.5.
• CUDA ≥ 12 recommended for full speed; MPS (Apple Silicon) and CPU also work.

Install the package into VoiceStudio's Python environment:

pip install "voxcpm>=2.0.3"

That is a version floor, not a pin — an older install still works, but the engine logs an upgrade hint at load time. Then select the engine via Model Catalogue → Engines or OMNIVOICE_TTS_BACKEND=voxcpm2.

The first use downloads a multi-GB checkpoint from HuggingFace. A download interrupted near the end used to abort the load outright (#1224); the load is now retried once with a fresh client. See downloading-models.md.

• Voice design: provide a description and no reference audio.
• Cloning: the reference clip is prepared before use (edge-silence trim and length cap) so dead air in a raw clip doesn't condition the output; on any prep problem the raw clip is used as-is.
• Style instructions are passed as an inline prefix to the text.
• VoxCPM2 emits mastered, studio-grade audio, so VoiceStudio skips its shared mastering chain (which is tuned for 24 kHz engines) — only benign loudness normalization applies.
• A trailing-silence guard trims long near-silent tails from generations, keeping a short natural tail.

• Slower than the lightweight CPU engines — see benchmarks.md and performance.md.
• Language coverage is 30 languages; for anything else use the default OmniVoice engine (languages.md).

• Engine shows unavailable: the voxcpm package isn't installed — run the pip install above and restart VoiceStudio.
• Repeated first-download failures: check connectivity/HF access, then see install/troubleshooting.md.

See also: expressive-speech.md, disk usage.