SPX to VOX conversion is the process of transforming audio stored in the Speex (.spx) format—an open-source, speech-oriented codec—into the Dialogic ADPCM VOX (.vox) format, a legacy telephony sample-based format. This conversion repackages or re-encodes audio so VOX-compatible telephony systems and legacy applications can play back voice recordings originally captured in SPX.
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Read guide →Drag your .SPX file from your computer or use the browse function.
Confirm .vox as the selected destination format.
Click "Convert" and download your converted .VOX file once ready.
SPX files typically use the audio/ogg MIME type and employ the Speex codec optimized for speech. VOX files usually have the audio/vox MIME type and use the Dialogic ADPCM codec, suitable for low-bandwidth voice applications. Both formats serve specialized voice recording use cases but differ in compatibility and compression methods.
The VOX (.VOX) format is commonly used for audio. Understanding its characteristics can be helpful when converting to or from other formats like SPX.
While specific technical details aren't available here, VOX files generally serve the purpose of storing audio effectively within their domain.
Looking to convert SPX audio files to VOX format without hassle? Our online SPX to VOX converter provides a simple and efficient solution to convert your SPX files directly in your browser. No software installation required.
SPX is an Ogg-based audio format commonly used for high-quality voice recordings, whereas VOX is a simpler audio format often used in telephony with smaller file sizes. While SPX supports better compression and quality, VOX is widely accepted by telephony hardware and software.
Keep input SPX files under 250 MB for free conversion to ensure speedy upload; consider splitting longer sessions if needed.
Preserve quality by matching sample rates where possible: convert wideband SPX to a compatible VOX sample rate only if target system supports it; otherwise downsample to 8 kHz for telephony.
For best results, normalize audio and remove background noise in the SPX source before conversion to avoid amplifying artifacts in the VOX ADPCM encoding.
Use batch conversion for multiple files, but monitor resulting file sizes—VOX files are small but long recordings may require segmentation.
This converter saved me hours with quick SPX to VOX conversion.
John M.
Audio Engineer
Easy to use and reliable for preparing files for telephony.
Lisa K.
Customer Support
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Podcaster
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Up to 250MB
Format limitation: VOX is mono and uses low-bit ADPCM; stereo, high-fidelity, or wideband nuances from SPX will be lost when converting to VOX.