Standing Wave 3 is an ActionScript 3 audio library that provides high-level control over the Flash Player’s SampleDataEvent API for streaming audio output. It builds on the foundation of Standing Wave 2 but has been extensively refactored, with its core sample storage and manipulation routines rewritten using Adobe Alchemy for significant performance improvements. Originally derived from the audio engine used in the Noteflight Score Editor, the library allows developers to combine and chain together audio sources, filters, and sequences to create dynamic, real-time sound experiences. Supported audio sources include MP3s, WAV files, and algorithmic generators, while filters enable effects such as echo, equalization, and envelope shaping. The system is flexible enough to handle complex timing sequences of audio, making it suitable for advanced audio applications or interactive projects.