XStream Sample Pack Guide

The .xsa Format

An .xsa file is a ZIP archive containing FLAC audio files and a manifest.json. It is designed for both Single mode (texture/loop playback) and Multi mode (one-shot granular synthesis).

pack-name.xsa  (ZIP archive)
├── manifest.json
└── samples/
    ├── sample-001.flac
    ├── sample-002.flac
    └── ...

{
  "name": "Fender Stratocaster",
  "version": "1.0",
  "instrument": "guitar",
  "mode": "single|multi|both",
  "channel_format": "mono|stereo|ambiX_1OA|ambiX_2OA",
  "root_note": "A3",
  "tuning": "standard",
  "samples": [
    {
      "file": "samples/sample-001.flac",
      "technique": "sustain",
      "pitch": "A3",
      "tempo": null,
      "mode_hint": "single"
    }
  ]
}

Channel Formats

File Naming Convention

Name sample files using the pattern: [instrument]-[technique]-[note]-[take].flac

strat-sustain-A3-01.flac
strat-harmonic-A3-01.flac
strat-palmmute-A3-01.flac
jazzmaster-swell-A3-01.flac
stick-tap-A3-01.flac
buchla-drone-A3-01.flac

Tonality Guidelines

Single Mode — Textures & Loops

Tonality is largely irrelevant for Single mode. Grains are pitch-shifted and time-stretched per the player's input, so even a dissonant source becomes workable material. By convention, center recordings around A as the root — playback at the default pitch sounds natural and unforced.

Multi Mode — One-Shots Mapped Across the Keyboard

Tonality matters for melodic content. A phrase recorded in a specific key will be pitch-shifted when triggered at other keys, which can clash musically.

• Melodic / harmonic content — record centered on A. Open-string resonance on standard-tuned guitars falls here naturally.
• Percussive / atonal hits — any pitch is fine. Granular pitch compensation makes it keyboard-playable regardless.
• Jazzmaster DADGAD / Open D — open strings define a D tonality. Document this in manifest.json ("tuning": "DADGAD", "root_note": "D3") so users know what to expect.

Instruments & Recording Plan

Recording Guidelines

Session Setup

Tempo

Pitch Reference for Multi Mode

One reference pitch per technique is sufficient — XStream's granular engine compensates for pitch across the full keyboard range.

• Record at A3 (220 Hz) as the standard reference for most instruments
• Bass register techniques (e.g. Stick bass side): record at A2 (110 Hz)
• Jazzmaster open-string content: record at D3 and document in manifest

What to Avoid

• Noise gates during the sustain body — they create unnatural grain dropouts
• Heavy compression before recording — granular already manages dynamics
• Reverb in the DAW — record dry, let XStream's spatializer handle space
• Clipping even by a sample — 24-bit has plenty of headroom at −6 dBFS

Release Phases

Verification & Testing

Before submitting a pack, verify the following:

1. Build the .xsa pack with a small test set (5–10 files) and load it into XStream
2. Single mode — confirm loop playback and that tempo-free content sounds natural
3. Multi mode — confirm one-shot triggering plays across the full pitch range without unwanted artifacts
4. Verify manifest.json parses correctly and sample metadata displays in the UI
5. Buchla packs only — confirm 4-channel FLAC loads and the ambiX signal routes correctly to the spatializer
6. Test on macOS and Windows — check path handling and ZIP extraction edge cases
7. Check noise floor: no audible hiss or hum in silent passages
8. Check headroom: no samples peaking above −6 dBFS