Here's the *.multisample xml file format and instructions to manually create it to load your own samples into Presence XT. If you need a good free (Windows) xml editor try the free editor here. http://www.yaldex.com/Free_JavaScript_Editor.htm
====================== Mutlisample File Format ======================
<?xml version="1.0" encoding="UTF-8"?>
Tags / Keywords
<multisample name="Kick Drums">
<generator>Studio One</generator>
<category>Drums, Strings (etc, etc)</category>
<creator>Your Name</creator>
<description>Description will show up in the PXT main screen</description>
<keywords>
<keyword>Drums</keyword>
<keyword>Modern</keyword>
</keywords>
The <layer> tag wraps the samples on that layer. It should allow multiple layers for different velocity layers but I haven't tried it yet.
<layer name="Default">
The <sample> tag wraps each individual sample / audio file. The stop value is a sample position value that has to match the file. The sample-stop sample value can't be more samples than the actual file has or the file will fail to load, If your xml file fails to load, trim a few samples from those numbers. You can get that value in Studio One by switching the timeline to samples, selecting a clip, and looking at the clip inspector.
<sample file="Kick1.wav" gain="0" tune="0" track="true"
<key high="36" low="36" root="36"/>
<velocity low="1" high="127" />
<loop mode="off" sample-start="0.000" sample-stop="4342"/>
</sample>
</layer>
</multisample>
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Saving the *.multisampler file.
1. Save the xml file as multisample.xml.
2. Zip it up along with all of the audio files with no compression.
3. Save the zip with a *.multisample file extender.
4. Drop it into Studio One to load or drop onto an existing PXT instance.