> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bland.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# BTTS v2 Voice Cloning

> How to create, configure, and optimize voice clones using BTTS v2.

## Introduction

BTTS v2 allows you to create custom voice clones from short audio samples. This guide covers how to create high-quality voice clones and format your text inputs for the best results.

To access the voice studio, go to:

[https://app.bland.ai/dashboard/voices?tab=studio](https://app.bland.ai/dashboard/voices?tab=studio)

***

## Creating a Voice Clone

To create a new voice clone:

1. Navigate to the **Voices Studio** tab
2. Click **New Voice**
3. Upload a 10–15 second audio sample

### Sample Requirements

For best results, your audio sample should have:

* Clear enunciation
* No background noise
* A single speaker
* At least 100ms of silence at the beginning and end (avoid cutting off mid-word)
* Emotional variety (for more expressive output)

> **Tip**: You can use [Audacity](https://www.audacityteam.org/) to edit and trim your clips. To download audio from YouTube videos, we recommend [yt-dlp](https://github.com/yt-dlp/yt-dlp).

***

## Configuration Settings

BTTS v2 provides two configuration options to fine-tune your voice clone.

### Speed vs. Smoothness

This setting controls how many frames the system waits for before decoding the first audio frame.

* **Lower values**: Faster initial audio output, but reduced quality in the first few hundred milliseconds
* **Higher values**: Smoother output, but potentially slower response time

### Clone Consistency Boost

This feature adds additional prompting to align output more closely with your original voice sample.

> **Important Note**: Disable Clone Consistency Boost if your agent needs to code-switch or speak multiple languages not present in your sample. If you're experiencing broken or distorted outputs, try toggling this setting off.

***

## Text Formatting

### Spacing Requirements

BTTS v2 processes text by splitting on spaces. Each word is generated individually, so proper spacing is essential for accurate output.

**Correct formatting:**

```text theme={null}
Hello <vocal burst> world.
```

**Incorrect formatting:**

```text theme={null}
Hello<vocal burst>world.
```

Hyphenated or concatenated words may cause reduced accuracy:

```text theme={null}
# Avoid
concatenated-word
from-the-same-array

# Preferred
concatenated word
from the same array
```

> **Note**: For Asian languages (Chinese, Japanese), the tokenizer handles character segmentation automatically—no manual spacing required.

***

## Text Normalization

The model automatically normalizes common text patterns before processing. You do not need to pre-format these inputs:

* **Emails**: `john@gmail.com` → `john @ gmail dot com`
* **URLs**: `www.google.com` → `www dot google dot com`
* **Smart quotes**: Converted to straight quotes
* **Repeated punctuation**: `Hello!!!` → `Hello!`
* **Missing spaces**: `End.Start` → `End. Start`

***

## Working with Numbers

For best results when generating numbers:

* Keep number sequences to 6 characters or fewer
* Format numbers as words when possible
* Always end sentences containing numbers with a period
* For long number strings, use pause tags to break up the generation

```text theme={null}
# Recommended
One two three four five.

# For long sequences, add pauses
One two three <|0.5|> four five six.
```

> **Important Note**: If your sentence does not end with proper punctuation, the model may drop the last number.

***

## Using Punctuation

Punctuation directly affects speech delivery in BTTS v2:

* **Ellipses (…)**: Adds pauses and weight
* **CAPITALIZATION**: Increases emphasis
* **Standard punctuation (. , !)**: Provides natural speech rhythm
* **Dashes (—)**: Can add stutters or breaks

***

## Best Practices

* Choose a voice sample with emotional variety for more expressive output
* Use natural speech patterns and proper punctuation
* Avoid unusual formatting (excessive dashes or ellipses) for timing control
* Always include proper spacing between words and tags
* End sentences with appropriate punctuation, especially when numbers are involved

***

Docs for agents: [llms.txt](/llms.txt)