AU vs WAV: Legacy Audio Format Comparison

Compare AU Sun Audio and WAV Windows audio formats.

Platform-Specific Audio Standards

AU (Sun Audio) was the audio standard for Sun Microsystems Unix systems and workstations (1980s-1990s). WAV (Windows Audio) was developed by Microsoft and IBM for Windows operating systems (1991). Both represent audio in digital form; both are uncompressed formats. The distinction: AU was Unix standard. WAV was Windows standard. Different platforms developed separate audio standards reflecting operating system ecosystems.

Technical Format Differences

AU uses Sun Audio format (AU file header specifying sample rate, channels, encoding). WAV uses RIFF container with chunks. Both store PCM audio (pulse code modulation). Technical approach differs: AU simpler, more streamlined. WAV more flexible with extensible chunk system. Both accomplish same goal (storing uncompressed audio) with different technical implementations.

Audio Quality and Specifications

Both AU and WAV support CD-quality audio (44.1 kHz, 16-bit) and higher resolutions. AU supports various sample rates and bit depths. WAV supports same. Quality is equivalent: both store perfect digital audio reproduction. No quality difference between AU and WAV at equivalent sample rates/bit depths.

File Size and Efficiency

Both AU and WAV are uncompressed formats, requiring substantial storage. A three-minute CD-quality song is approximately 30 MB in both formats. Neither format offers compression. Size is identical for equivalent audio specifications. Historical context: uncompressed storage was acceptable when disk space was expensive and audio was professionally archived.

Platform Adoption and Ecosystem

AU dominated Unix/Linux systems, Sun workstations, and some scientific/professional audio applications. WAV dominated Windows systems and consumer audio. The platform divide was clear: if you used Unix, AU was standard. If you used Windows, WAV was standard. Cross-platform systems supported both.

Modern Support and Compatibility

WAV support is nearly universal on modern systems: all major platforms, media players, and applications support WAV. AU support is limited to legacy systems, some Linux tools, and specialized audio software. WAV universality reflects its broader adoption; AU is now platform-specific legacy.

Software Tools and Libraries

WAV libraries exist for every programming language and platform. AU libraries are less common, primarily in legacy Unix/Linux environments and specialized audio applications. Tool availability heavily favors WAV for modern development.

Streaming and Distribution

Neither AU nor WAV is practical for streaming: file sizes are too large. Both were archived and transferred locally (offline). MP3 replaced both for streaming, making original platform distinction irrelevant.

Historical Significance and Legacy

Both AU and WAV represent the era when operating systems had distinct audio standards. Modern audio is platform-agnostic: codecs like MP3, AAC, FLAC work universally. Understanding AU vs WAV provides historical context for audio technology evolution. Both formats persist in legacy systems but are not recommended for new applications.