# WAV Files

You may optionally include WAV files in the root directory of the SD card. Up to two of these sound files can be played simultaneously along with the vocalizer.

{% hint style="warning" %}
WAV files must be in 16-bit, 44.1kHz format.
{% endhint %}

{% hint style="warning" %}
A micro SD card rated [V30 or faster](https://www.sdcard.org/developers/sd-standard-overview/speed-class/) is required for WAV playback. A slower SD card will cause pops and audio dropouts.
{% endhint %}

## Naming WAV Files

WAV files must be formatted with a numerical prefix in this format:

```
[number][name].WAV
```

...where `[number]` is a 4 digit number and `[name]` is any name of your choosing for labeling purposes.

For example, your files might include:

```
0000Hologram.WAV
0001BrassSymphony.WAV
9566Explosion.WAV
```

## Playing WAV Files

Use [commands](/r2d2/platforms/embedded/commands.md) to play a WAV file on either channel A or channel B.

`<CA0001>` — Play a WAV file with a file name beginning with "0001" on channel A.

`<CB0326>` — Play a WAV file with a file name beginning with "0326" on channel B.

`<CA0007C0022>` — Play a WAV file with a file name beginning with a number between "0007" and "0022" on channel A.

{% hint style="warning" %}
If you plan on using WAV files to play multiple sources simultaneously (vocalizer + WAV channel A, WAV channel A + WAV channel B, etc), be sure to use the volume [commands](/r2d2/platforms/embedded/commands.md) to lower the volume of those sources as described in [Volume Setup](/r2d2/platforms/embedded/volume-adjustment.md).
{% endhint %}

## Migrating From an MP3Trigger System

You may convert your old MP3s to WAVs using free software.

WAV files are a "lossless" audio format. They contain more data and are capable of higher quality than MP3s, which are a "lossy" format.

However, note that converting from an MP3 to a WAV will not recover lost sound quality. It will simply create a WAV that sounds identical to the lossy MP3.

You can improve the quality of your system by seeking out the original lossless audio files.


---

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```
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```

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