What is XM?

Extended Module (XM) is the native format of Fast Tracker II, supporting samples, patterns, effects, and volume envelopes.

What is SPX?

Speex, open-source speech codec for VoIP and voice — stored as audio/speex — uses lossy encoding to handle voip telephony, voice chat, speech compression. Typical file sizes: varies by content.

When Should You Use XM vs SPX?

XM vs SPX: Key Differences

• •XM uses lossless compression while SPX uses lossy compression — this is the fundamental technical difference between the two formats.
• •Moving from XM (lossy) to SPX (lossy) means the output file will be significantly smaller — but at the cost of some visual fidelity.
• •Transparency: Not supported in SPX — converting from XM will merge transparency into a solid background
• •SPX files tend to be differently sized than XM
• •XM is optimized for tracker music, demoscene, retro game audio while SPX is designed for voip telephony, voice chat, speech compression — choose based on your specific workflow needs

Advantages of XM

• ✓XM uses lossless compression tailored for Tracker music, demoscene, retro game audio.
• ✓XM is supported natively on virtually every device, browser, and operating system.
• ✓XM files are bit-for-bit perfect, preserving every pixel and sample for professional work.
• ✓XM integrates seamlessly with all major creative tools and workflows.

Advantages of SPX

• ✓SPX uses lossy compression tailored for VoIP telephony, voice chat, speech compression.
• ✓SPX is supported natively on virtually every device, browser, and operating system.
• ✓SPX files are compact and quick to transfer, even over slow connections.
• ✓SPX integrates seamlessly with all major creative tools and workflows.

Common Use Cases for XM to SPX Conversion

• Music education
• Conference call recordings
• Field recording preservation
• Music production and mixing
• Podcast distribution
• Voice recordings

Industry Applications

Best Practices for XM to SPX Conversion

• →Converting XM to SPX: SPX preserves full audio fidelity — ideal for archiving master recordings
• →Normalize audio levels before conversion for consistent playback volume
• →SPX excels in professional audio workflows
• →Always keep a backup of your original files before converting
• →Choose the appropriate quality settings for your specific use case

Related Article

Troubleshooting XM to SPX Conversion

• !Clicks or pops in the converted SPX → sample rate conversion can introduce artifacts; use a clean multiple of the source rate
• !SPX file has silence at the beginning or end → trim the source XM file before converting to avoid unnecessary padding
• !Stereo image collapsed after converting XM to SPX → verify that the converter preserves channel mapping for multichannel audio
• !The converted SPX clips or distorts at peaks → reduce the gain or apply a limiter before conversion to prevent hard clipping

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