CONVERT SPX → WV (SPX to WV)
Fast, secure SPX to WV conversion. No registration required.
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HOW TO CONVERT SPX → WV
Give us the SPX
Select a SPX (or several for batch). We read the header to pick decoder settings automatically.
Re-encode to WV
The audio is decoded, optionally resampled, and re-encoded as WV at transparent default bitrate.
Retrieve your WV
Grab the download as soon as it is ready. Typical jobs finish in seconds for short clips.
Opening note — SPX is an audio format with specific trade-offs between file size, bitrate flexibility, and device support. The WV you want is two clicks away. Turn your SPX audio into a widely-supported WV file. The conversion happens server-side through FFmpeg — the same engine behind every major audio editor — so the output plays cleanly on phones, car stereos, DJ software and streaming tools. A quick refresher — SPX is an audio format with specific trade-offs between file size, bitrate flexibility, and device support. By contrast, WV is WavPack's hybrid lossless/lossy audio codec with a correction-file workflow.
Why convert SPX to WV
The motivation for a SPX → WV conversion is almost always practical: a playback device, hosting platform or editing suite that insists on WV. The audio quality trade-off is controllable via bitrate; the compatibility win is immediate and unambiguous.
SPX vs WV — Technical specifications
Side-by-side comparison of the technical details.
SPX
- MIME type
- audio/speex
- Extension
- .spx
- Container
- Ogg
- Modes
- Narrowband/Wideband/Ultra-wideband
- Successor
- Opus
- MIME Type
- audio/x-speex
- Category
- Audio Files
- Full Name
- Speex Audio
- Conversion Engine
- FFMPEG
WV
- MIME type
- audio/x-wavpack
- Extension
- .wv (main), .wvc (correction)
- Modes
- Lossless, Hybrid lossy+correction, 32-bit float
- MIME Type
- audio/x-wavpack
- Category
- Audio Files
- Full Name
- WavPack Audio
- Conversion Engine
- FFMPEG
- License
- BSD-style
| Specification | SPX | WV |
|---|---|---|
| MIME type | audio/speex | audio/x-wavpack |
| Extension | .spx | .wv (main), .wvc (correction) |
| Container | Ogg | — |
| Modes | Narrowband/Wideband/Ultra-wideband | Lossless, Hybrid lossy+correction, 32-bit float |
| Successor | Opus | — |
| MIME Type | audio/x-speex | audio/x-wavpack |
| Category | Audio Files | Audio Files |
| Full Name | Speex Audio | WavPack Audio |
| Conversion Engine | FFMPEG | FFMPEG |
| License | — | BSD-style |
SPX vs WV — Strengths and limitations
What each format does best, and where it falls short.
SPX Strengths
- Patent-free voice codec.
- Three sample-rate modes for voice.
- Low CPU decode.
Limitations
- Deprecated in favor of Opus.
- No music support.
- Rarely used in new projects.
WV Strengths
- Hybrid lossy/lossless mode.
- Supports DSD, 32-bit float, multichannel.
- Competitive compression vs FLAC.
- Active maintenance since 1998.
Limitations
- Small ecosystem.
- Hybrid mode complexity.
- Hardware support limited vs FLAC.
Quality & Compatibility
The WV output is as good as the SPX source allows. If the SPX was encoded at 96 kbps, the WV cannot reconstruct detail the encoder already dropped; picking a very high WV bitrate just produces a larger file. Match WV bitrate to the SPX quality for the best balance.
Tips for Best Results
- Sample-rate mismatches between SPX and target device (48 kHz phone output from a 44.1 kHz track) are handled automatically; no manual resampling needed.
- For audiobook delivery, match the platform spec exactly — ACX requires 192 kbps CBR 44.1 kHz stereo, for example.
- Batch-convert an album in one job so every track shares identical encoder settings and loudness normalisation.
Frequently Asked Questions
Lossy-to-lossy conversions (most combinations) re-compress the audio, which technically introduces some loss. At a 192 kbps or higher target it is inaudible on normal equipment. Lossy-to-lossless conversions freeze the existing quality but cannot improve it; lossless-to-lossy transcodes are only as good as the target bitrate you choose.
For voice content (podcasts, audiobooks, lectures) 128 kbps is indistinguishable from higher bitrates. For music, 192-256 kbps covers most listening; 320 kbps is the ceiling for WV and the right choice for audio you plan to edit further. Above that, prefer a lossless target instead.
Yes. Title, artist, album, year and cover art travel from the SPX container to the WV container automatically where both formats support them. If a tag field has no WV equivalent, it is dropped silently. Use any tag editor (Mp3tag, MusicBrainz Picard) to fine-tune afterwards.
Speex Audio
Source formatSpeex 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.
WavPack Audio
Target formatWavPack is an open-source audio codec that offers lossless, lossy, and hybrid compression modes. Its unique hybrid mode creates a lossy file plus a correction file that together reconstruct the original, enabling flexible storage strategies.
Going the other way? Convert WV back to SPX with the same engine.
Common Use Cases
Share across platforms
Send WV files to anyone without worrying about whether they have the right software for SPX.
Embed in documents
Drop WV output into Word, Google Docs, PowerPoint, Notion or a website without conversion warnings.
Optimize size
WV often produces smaller files than SPX for web, email and storage.
Archive & future-proof
Store in a widely-supported format that will still open on future operating systems without legacy plugins.
SPX vs WV — Typical file sizes
Approximate file sizes for common scenarios.
- 1 min voice (wideband 24 kbps) ~180 KB
- 3-min song (CD lossless) 18-24 MB
- 3-min hi-res 24/96 60-90 MB
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Related comparisons
See these formats side by side to understand which fits your use case best.
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