Model reference · open weights

kugelaudio-0-open

Available as managed deployment Audio kugelaudio Text→speech 1 variants 2k dl/mo

kugelaudio-0-open is an open-weight audio or speech model from kugelaudio. AxForge deploys and operates it for you on dedicated EU-owned hardware — with the licence handled where one is required.

Available as managed deployment — configured and operated for you on dedicated EU hardware, quoted per deployment.

What it is

Released bykugelaudio
TypeAudio & music
TaskText→speech
Parameters (lead)9.3B
Released2026-01-11
Popularity2k downloads / month
LicenceOpen weights

About

What kugelaudio-0-open is

Open-source text-to-speech for European languages 7B parameter model powered by an AR + Diffusion architecture

License: MIT Python 3.10+ Hosted API

KugelAudio KI-Servicezentrum Berlin-Brandenburg Gefördert durch BMFTR


Read the full model card

Motivation

Open-source text-to-speech models for European languages are significantly lagging behind. While English TTS has seen remarkable progress, speakers of German, French, Spanish, Polish, and dozens of other European languages have been underserved by the open-source community.

KugelAudio aims to change this. Building on the excellent foundation laid by the VibeVoice team at Microsoft, we've trained a model specifically focused on European language coverage, using approximately 200,000 hours of highly pre-processed and enhanced speech data from the YODAS2 dataset.

🏆 Benchmark Results: Outperforming ElevenLabs

KugelAudio achieves state-of-the-art performance, beating industry leaders including ElevenLabs in rigorous human preference testing. This breakthrough demonstrates that open-source models can now rival - and surpass - the best commercial TTS systems.

Human Preference Benchmark (A/B Testing)

We conducted extensive A/B testing with 339 human evaluations to compare KugelAudio against leading TTS models. Participants listened to a reference voice sample, then compared outputs from two models and selected which sounded more human and closer to the original voice.

German Language Evaluation

The evaluation specifically focused on German language samples with diverse emotional expressions and speaking styles:

  • Neutral Speech: Standard conversational tones
  • Shouting: High-intensity, elevated volume speech
  • Singing: Melodic and rhythmic speech patterns
  • Drunken Voice: Slurred and irregular speech characteristics

These diverse test cases demonstrate the model's capability to handle a wide range of speaking styles beyond standard narration.

OpenSkill Ranking Results

RankModelScoreRecordWin Rate
🥇 1KugelAudio2671W / 20L / 23T78.0%
🥈 2ElevenLabs Multi v22556W / 34L / 22T62.2%
🥉 3ElevenLabs v32164W / 34L / 16T65.3%
4Cartesia2155W / 38L / 19T59.1%
5VibeVoice1030W / 74L / 8T28.8%
6CosyVoice v3915W / 91L / 8T14.2%

Based on 339 evaluations using Bayesian skill-rating system (OpenSkill)

Audio Samples

Listen to KugelAudio's diverse voice capabilities across different speaking styles and languages:

German Voice Samples

SampleDescriptionAudio Player
WhisperingSoft whispering voice
Female NarratorProfessional female reader voice
Angry VoiceIrritated and frustrated speech
Radio AnnouncerProfessional radio broadcast voice

All samples are generated using pre-encoded voice embeddings.

Training Details

  • Base Model: Microsoft VibeVoice
  • Training Data: ~200,000 hours from YODAS2
  • Hardware: 8x NVIDIA H100 GPUs
  • Training Duration: 5 days

Supported Languages

This model supports the following European languages:

LanguageCodeFlagLanguageCodeFlagLanguageCodeFlag
Englishen🇺🇸Germande🇩🇪Frenchfr🇫🇷
Spanishes🇪🇸Italianit🇮🇹Portuguesept🇵🇹
Dutchnl🇳🇱Polishpl🇵🇱Russianru🇷🇺
Ukrainianuk🇺🇦Czechcs🇨🇿Romanianro🇷🇴
Hungarianhu🇭🇺Swedishsv🇸🇪Danishda🇩🇰
Finnishfi🇫🇮Norwegianno🇳🇴Greekel🇬🇷
Bulgarianbg🇧🇬Slovaksk🇸🇰Croatianhr🇭🇷
Serbiansr🇷🇸Turkishtr🇹🇷

📊 Language Coverage Disclaimer: Quality varies significantly by language. Spanish, French, English, and German have the strongest representation in our training data (~200,000 hours from YODAS2). Other languages may have reduced quality, prosody, or vocabulary coverage depending on their availability in the training dataset.

Model Specifications

PropertyValue
Parameters7B
ArchitectureAR + Diffusion (Qwen2.5-7B backbone)
Base ModelMicrosoft VibeVoice
Audio Sample Rate24kHz
Audio FormatMono, float32
VRAM Required~19GB
Training Hardware8x NVIDIA H100
Training Duration5 days
Training Data~200,000 hours from YODAS2

Quick Start

Installation

# Install with pip
pip install kugelaudio-open

# Or with uv (recommended)
uv pip install kugelaudio-open

Basic Usage

from kugelaudio_open import (
    KugelAudioForConditionalGenerationInference,
    KugelAudioProcessor,
)
import torch

# Load model
device = "cuda" if torch.cuda.is_available() else "cpu"
model = KugelAudioForConditionalGenerationI

From the published model card. Full card on the HuggingFace links in the sidebar.

Benchmarks

Reported results

As published on the model card — the maker's own numbers, not measured by AxForge.

TaskDatasetMetricScore
text-to-speechYODAS2Human Preference vs ElevenLabs78

Using it via the API

Call it like any OpenAI endpoint

Once AxForge deploys kugelaudio-0-open for you, it answers on the OpenAI-compatible API — the same base URL and keys as every other model. (kugelaudio-0-open below is illustrative; you get the exact model name on deployment.)

$ curl -sS https://api.axforge.ai/v1/audio/transcriptions \
  -H "Authorization: Bearer $AXFORGE_API_KEY" \
  -F model="kugelaudio-0-open" -F file=@audio.mp3

Create an account — your API key is available in the console. 3M free tokens every 30 days with every new account.

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