🖥️ Self-Hosted Audio AI Models
Deep Research Report: Post-Kimi-Audio Landscape (December 2025)
📋 Executive Summary
Kimi-Audio (May 2025) remains a strong contender, but several models have surpassed or matched it in specific areas since its release. The audio AI landscape has evolved rapidly, with specialized models now outperforming general-purpose solutions in their respective domains.
🎯 Best ASR
Voxtral (Mistral) - Beats Whisper & GPT-4o-mini
🗣️ Best TTS
OpenAudio S1 (Fish Audio) - #1 on TTS-Arena2
🧠 Best Understanding
Audio Flamingo 3 (NVIDIA) - Chain-of-thought reasoning
💬 Best Conversation
Sesame CSM - "Better than OpenAI Voice Mode"
📊 Head-to-Head Comparison Matrix
| Model | Release | ASR | TTS | Understanding | Generation | Conversation | Self-Hosted |
|---|---|---|---|---|---|---|---|
| Kimi-Audio | May 2025 | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ✅ |
| Voxtral | Jul 2025 | ⭐⭐⭐⭐⭐ | ❌ | ⭐⭐⭐⭐ | ❌ | ❌ | ✅ |
| Audio Flamingo 3 | Jul 2025 | ⭐⭐⭐⭐⭐ | ❌ | ⭐⭐⭐⭐⭐ | ❌ | ✅ (v2v) | ✅ |
| OpenAudio S1 | Jun 2025 | ❌ | ⭐⭐⭐⭐⭐ | ❌ | ⭐⭐⭐⭐⭐ | ❌ | ✅ |
| Step-Audio | Feb 2025 | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ✅ |
| Qwen2.5-Omni | Mar 2025 | ⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐⭐⭐ | ✅ |
| NVIDIA UALM | Oct 2025 | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⚠️ Research |
🏆 Models Ahead of or Competitive with Kimi-Audio
These models have surpassed Kimi-Audio in specific domains since its May 2025 release.
Voxtral (Mistral AI)
State-of-the-Art ASR, beats Whisper & GPT-4o-mini in transcription
July 2025
24.3B / 4.7B
Apache 2.0
Parameters
24.3B (Small) / 4.7B (Mini)
Streaming Latency
~150ms
Languages
100+
Source
SOTA ASR
Transcription
Translation
Voice Commands
Audio Generation
Conversation
VERDICT
Superior for transcription/translation, but narrower scope than Kimi-Audio. Best for: Transcription, translation, voice command input.
Audio Flamingo 3 (NVIDIA) ⭐
Chain-of-thought reasoning, outperforms Gemini 2.5 Pro
July 2025
7B (Qwen2.5-7B)
Non-Commercial
ClothoAQA
91.1%
LibriSpeech WER
1.57%
MMAU
73.14%
Audio Context
10+ minutes
Chain-of-Thought
Audio Understanding
Audio Captioning
Complex Q&A
TTS
Audio Generation
VERDICT
Outperforms Gemini 2.5 Pro and Qwen2.5-Omni. Strong competitor to Kimi-Audio with better reasoning capabilities. Best for: Audio analysis, captioning, complex audio Q&A.
OpenAudio S1 (Fish Audio)
#1 ranked on TTS-Arena2, surpassing ElevenLabs and OpenAI
June 2025
4B / 0.5B
Open Source
Best TTS Quality
Voice Cloning
Emotion Control
RLHF Fine-tuned
Audio Understanding
Conversation
VERDICT
Best pure TTS quality available, surpassing ElevenLabs and OpenAI. More specialized than Kimi-Audio's universal approach. Best for: Voice synthesis, voice cloning, audiobook narration, scratch vocals.
Step-Audio (StepFun AI)
Most comprehensive production-ready framework
February 2025
130B / 3B
Open Source
Chat Model
130B parameters
TTS Model
3B parameters
Architecture
Dual-codebook (16.7Hz + 25Hz)
Source
Multilingual
Emotional TTS
Dialect Support
Voice Cloning
Full Pipeline
VERDICT
Most comprehensive open-source audio system. 130B model is massive but powerful. Best for: Full-featured voice assistants, multilingual applications.
NVIDIA UALM 🔥
First cross-modal generative reasoning
October 2025
7B unified
Research Only
Innovation
Cross-modal reasoning
Capabilities
Understanding + Generation + Reasoning
Hardware
Requires A100 GPU
Source
Text+Audio Thinking
Audio Understanding
Audio Generation
Audio-to-Audio
Unified Architecture
VERDICT
Most advanced architecture with multimodal reasoning (text + audio in thinking steps). Strong future competitor. Best for: Research, complex audio reasoning, future production systems.
🔍 Kimi-Audio Deep Dive
Understanding the baseline: Kimi-Audio's architecture, capabilities, and limitations.
Kimi-Audio (Moonshot AI)
Universal audio foundation model - understand + generate + converse
May 2025
12B LLM
Open Source
Architecture
Base LLM
12B parameters
Audio Encoder
Whisper-large-v3 based
Audio Tokenizer
12.5Hz semantic + acoustic
Context Length
128K tokens
Training Data
13M hours
Vocoder
Flow-matching based
Capabilities
Audio Understanding
- Speech recognition (ASR)
- Audio captioning
- Sound event detection
- Emotion recognition
- Speaker identification
Audio Generation
- Text-to-speech (TTS)
- Voice cloning
- Audio continuation
- Sound effect generation
Speech Conversation
- End-to-end voice chat
- Turn-taking
- Interruption handling
- Context maintenance
Benchmark Performance
| Benchmark | Kimi-Audio | GPT-4o | Gemini 1.5 Pro |
|---|---|---|---|
| LibriSpeech WER | 1.28% | 2.5% | 3.1% |
| CommonVoice WER | 5.3% | 7.2% | 6.8% |
| AudioCaps (CIDEr) | 82.4 | - | - |
| MMAU Understanding | 68.2% | 62.1% | 65.3% |
Limitations
- Inference Speed: Not optimized for real-time streaming
- Music Understanding: Weaker than speech understanding
- Long Audio: Degrades on audio >10 minutes
- Voice Quality: TTS not as natural as specialized models
👀 Emerging Models to Watch
Sesame CSM
"Sounds better than OpenAI Advanced Voice Mode" - 1B params, real-time streaming, Apache 2.0
Orpheus TTS
100-200ms latency, multi-language, tag-based emotion control (<laugh>, <whisper>)
Dia 2
Nov 2025 - Dialogue-first TTS with non-verbal sounds, multi-speaker support
CosyVoice 2
150ms ultra-low latency streaming, Alibaba, production-ready
Chatterbox
First emotion exaggeration control in open-source, 5-second voice cloning
🔑 Key Findings
Where Kimi-Audio Still Leads
- Universal audio foundation - best all-in-one for understanding + generation + conversation
- 13M hours pretraining - most diverse audio training data
- End-to-end speech conversation - few competitors match this
Where Kimi-Audio Has Been Surpassed
- Pure ASR: Voxtral beats it (1.28 WER vs Voxtral's better scores on multilingual)
- Pure TTS: OpenAudio S1 now #1 on TTS-Arena2
- Audio Reasoning: Audio Flamingo 3 introduces chain-of-thought thinking
- Multimodal Reasoning: NVIDIA UALM does cross-modal reasoning (text+audio thinking)
- Production Scale: Step-Audio 130B is more comprehensive
🎛️ Recommendations for FlowState DAW
| Need | Best Choice | Why |
|---|---|---|
| All-in-one audio | Kimi-Audio or Step-Audio | Universal capabilities |
| Best transcription/translation | Voxtral | SOTA ASR, Apache 2.0 |
| Best TTS quality | OpenAudio S1 | #1 on benchmarks |
| Audio understanding + reasoning | Audio Flamingo 3 | Chain-of-thought |
| Low-latency conversation | Sesame CSM or CosyVoice 2 | Real-time streaming |
| Voice assistant voice | Sesame CSM | Most natural |
| Scratch vocals | OpenAudio S1 | Best quality |
| Voice cloning | OpenVoice V2 or Orpheus | Zero-shot cloning |
Bottom Line: For a DAW, you likely want a combination rather than relying on a single model. Kimi-Audio is no longer the undisputed leader (May 2025 is "old" by AI standards), but it remains one of the most complete universal audio models.
📚 Sources
- github.com/MoonshotAI/Kimi-Audio
- mistral.ai/news/voxtral
- research.nvidia.com/labs/adlr/AF3/
- speech.fish.audio
- github.com/stepfun-ai/Step-Audio
- research.nvidia.com/labs/adlr/UALM/
- blog.google (Gemini Audio Updates)
- github.com/SesameAILabs/csm
- github.com/nari-labs/dia
- github.com/canopyai/Orpheus-TTS
- github.com/FunAudioLLM/CosyVoice
- github.com/myshell-ai/OpenVoice
Research compiled December 2025. Model availability and licensing subject to change.