FLAC vs SPX
A detailed comparison of FLAC Audio and Speex Audio — file size, quality, compatibility, and which format to choose for your workflow.
FLAC Audio
Audio FilesFLAC is an open-source lossless audio codec that compresses audio to roughly 50-60% of its original size without any quality loss. It is the preferred format for audiophiles and music archival.
About FLAC filesSpeex Audio
Audio FilesSpeex is an open-source audio compression format specifically designed for speech encoding. It uses Code-Excited Linear Prediction (CELP) and supports narrowband, wideband, and ultra-wideband modes for different speech quality requirements.
About SPX filesStrengths Comparison
FLAC Strengths
- Lossless — decoded audio is bit-exact identical to the source.
- 40-60% smaller than uncompressed WAV/AIFF.
- Free, patent-free, open-source reference implementation.
- Built-in error detection via MD5 checksums.
- Streaming-friendly — seek tables let you jump to any timestamp instantly.
SPX Strengths
- Patent-free voice codec.
- Three sample-rate modes for voice.
- Low CPU decode.
Limitations
FLAC Limitations
- File sizes still large compared to lossy codecs (5-10× bigger than AAC for same audio).
- Not suitable for low-bandwidth scenarios like streaming on mobile data.
- Older MP3 players and car stereos may not decode FLAC.
- Slower to encode than lossy codecs.
SPX Limitations
- Deprecated in favor of Opus.
- No music support.
- Rarely used in new projects.
Technical Specifications
| Specification | FLAC | SPX |
|---|---|---|
| MIME type | audio/flac | audio/speex |
| Extension | .flac | .spx |
| Standard | Open-source reference implementation (Xiph.Org) | — |
| Max bit depth | 32 bits per sample | — |
| Max sample rate | 655 350 Hz | — |
| Max channels | 8 | — |
| Container | — | Ogg |
| Modes | — | Narrowband/Wideband/Ultra-wideband |
| Successor | — | Opus |
Typical File Sizes
FLAC
- 3-min song (CD quality) 20-30 MB
- Full album (10 tracks, CD) 250-400 MB
- 3-min song (hi-res 24-bit/96 kHz) 80-120 MB
- Live concert recording (24-bit) 2-10 GB
SPX
- 1 min voice (wideband 24 kbps) ~180 KB
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Frequently Asked Questions
FLAC (Free Lossless Audio Codec) is an open-source audio format that compresses audio without any quality loss. Developed by the Xiph.Org Foundation, it typically reduces file sizes by 40-50% compared to WAV while preserving bit-perfect audio.
FLAC (Free sem perdas Audio codec) is an open-source audio formato that compresses audio sem any quality loss. Developed pelo Xiph.Org Foundation, it tipicamente reduces tamanho do arquivos by 40-50% comparado a WAV while preserving bit-perfect audio.
FLAC files play in VLC, foobar2000, Winamp, and most modern music players. Streaming services like Tidal and Amazon Music HD use FLAC. Android supports it natively, and Apple devices support it via third-party apps.
FLAC arquivos reproduzir in VLC, foobar2000, Winamp, e most moderno music players. Streaming services like Tidal e Amazon Music HD usar FLAC. Android suporta it natively, e Apple devices support it via third-party apps.
Both are lossless with similar compression ratios. Use FLAC for universal compatibility and open-source support. Use ALAC if you are fully invested in the Apple ecosystem since iTunes and Apple Music handle ALAC natively.
Both are sem perdas com similar compressão ratios. usar FLAC para universal compatibilidade e open-source support. usar ALAC if you are fully invested no Apple ecosystem since iTunes e Apple Music handle ALAC natively.