Ensembling impossible - model not visible in vocal splitter in UVR

- If user-imported Roformers aren't recognized in "instrumental/vocals" in ensemble or in vocal splitter, but are in "multi-stem ensemble":
“The .yaml associated with the model usually needs to be updated to match UVR's stem naming conventions. For example, if your config shows the instruments as "other" and "vocals", it will need to be updated to "Instrumental" and "Vocals" (case-sensitive)” - Anjok

E.g. for Karaoke models, you need to change “Karaoke” to “Vocals”.

But you can also use Tools>Manual Ensemble instead for ready separations.

 

Ensemble vs multi-stem ensemble explained (by stephanie)

 

“The multi-stem ensemble mode is designed to ensemble every stem in all the models that were selected. I'll explain how it's related:

Let’s say you have two vocal/instrumental models selected, and two 4-stem models selected (vocals, drums, bass, other), then it will process the song through all of the models. As a result, the final ensembled output will be 5 stems: vocals, instrumental, drums, bass, and other.

 

The drums, bass, and other stems will just be the ensemble of the 2 models in that selection that shared those outputs. However, all models in that particular selection shared a vocal output so it will be the ensemble of each model's vocal output

I'm not sure if that's very clear, but that's how it works and why the way it handles each stem is different from the other stem pair modes”

- Roformers might be sometimes slow/stuck/give memory allocation error during separation on AMD/Intel GPUs with VRAM lower than 16GB, if you don’t lower default “chunk_size” during importing the model, or in the corresponding yaml in: models\MDX_Net_Models\model_data\mdx_c_configs
or in Choose Model>Edit Models Config>Change Parameters>Edit Model Param.

So even if separation works, it can be unnecessarily slow with too big chunks esp. on AMD/Intel GPUs on DirectML.
Start with min. chunk_size = 112455 (dim_t 256 equivalent) and increase it depending on GPU or model size till you start getting errors to get the best possible SDR.

 

For older beta 1-9 and 4GB VRAM GPUs, lower dim_t at the bottom of the yaml (not at the top) to e.g. 256 or 201, sometimes 301 - some Roformers will require lower dim_t/chunk_size - the higher, the better till 1101, or training chunks value in the config.

So since patch #10 “new beta version[s] doesn't rely on 'inference.dim_t' value anymore (if you were using edited "dim_t" value).

Now you have to edit audio.chunk_size now “In the model yaml config file, at top of it, chunk_size is the first parameter (...) you can edit model config files directly inside UVR now.