Nemotron-Labs-Audex-2B

Nemotron-Labs-Audex-2B Introduction We're excited to introduce Nemotron-Labs-Audex-2B, a unified audio-text LLM with a similar recipe as Nemotron-Labs-Audex-30B-A3B. Audex-2B extends the vocabulary for discrete audio tokens used for speech and general audio outputs, as well as an audio encoder for speech and general audio inputs. Audex-2B delivers strong abilities on audio tasks (audio understanding, speech recognition and translation, text-to-speech, audio generation, and speech-to-speech generation) while preserving very compelling reasoning, alignment, knowledge, long-context, and agentic capabilities of its text-only LLM backbone with marginal or no regression. Audex-2B operates in both **thinking** and **instruct** (non-thinking) modes. Model Architecture Templates Multi-Stage-SFT and Cascaded-RL Pipelines Audex-2B Details Audex-2B is a compact, dense model trained using the same multi-stage SFT recipe as Audex-30B-A3B. Its smaller size reduces inference resource requirements. Audex-2B is released after multi-stage SFT, while Audex-30B-A3B additionally undergoes cascaded RL. Quick Start Audex-2B follows the ChatML template and supports both thinking and instruct (non-thinking) modes. Reasoning content is enclosed within ` ` and ` ` tags. To activate the instruct (non-thinking) mode, we prepend ` ` to the beginning of the assistant’s response. Audex-2B supports up to a 128K-token context length. Audex-2B follows Nemotron-Cascade-2 on text evaluation. Audex-2B has different recommended inference setups per audio-related task as described below. Environment We use **vLLM 0.20.0 container image**: vllm/vllm-openai:v0.20.0-cu129 **vLLM inference** — text-only reasoning, text-to-speech, text-to-audio, and audio understanding / speech recognition / speech translation: runs on **vLLM 0.20.0**. **Hugging Face / transformers inference** — requires transformers >= 4.53.0 (tested with 4.53.3) and also works with transformers >= 5.0. Audio extras:** image does not include a