SD2 to VOX Converter

High-quality SD2 to VOX conversion online

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Cross-Platform

Convert SD2 to VOX on any operating system through your web browser. Works equally well on desktops, laptops, and phones.

Intuitive Process

The SD2 to VOX converter is designed for simplicity. Upload, convert, download — done in under a minute.

Secure Conversion

Your SD2 uploads are deleted immediately after conversion. VOX output files are removed from our servers within 24 hours.

How to convert SD2 to VOX

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose vox or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your vox file right afterwards

About formats

Sound Designer II (SD2) is a professional audio format created by Digidesign around 1988 as the successor to the original Sound Designer format. For over a decade, SD2 was the standard interchange format in professional recording studios, especially those on Macintosh systems. It stores uncompressed linear PCM audio at up to 24-bit resolution with sample rates used in professional production (44.1, 48, 88.2, and 96 kHz). A distinctive technical trait is its reliance on the classic Mac OS resource fork for critical metadata — sample rate, bit depth, and channel configuration — while audio data resides in the data fork. This design worked elegantly within the Mac ecosystem but created portability challenges when files moved to Windows or Unix. A key advantage was SD2's support for multiple channels in a single file and tight integration with the Pro Tools editing environment, enabling non-destructive region-based editing. The format also carried loop points and markers, making it valuable for sample libraries. As Avid Technology shifted Pro Tools toward WAV and AIFF, SD2 usage declined, but millions of legacy session archives still contain SD2 files needing occasional conversion.
Initial release: 1988
VOX is a headerless audio format built around Dialogic ADPCM encoding, widely adopted in telephony, interactive voice response (IVR) systems, and voice mail platforms since the 1980s. Each audio sample is compressed into 4 bits using an algorithm developed by Oki Electric and implemented in hardware on Dialogic Corporation's telephony interface cards. VOX files typically use a sampling rate of 6000 or 8000 Hz, producing extremely compact recordings optimized for speech intelligibility rather than musical fidelity. Because the format carries no header, playback software must know the sample rate and encoding parameters in advance — a trade-off that reduces overhead but demands careful file management. The primary advantage of VOX is storage efficiency: a one-minute voice recording at 8 kHz occupies roughly 240 KB, making it practical for systems storing thousands of prompts. Dialogic ADPCM conforms to the ITU-T G.726 standard, ensuring interoperability across telephony equipment from different vendors. Even as modern call centers migrate to IP-based systems with codecs like Opus, vast libraries of VOX recordings persist in legacy IVR deployments and compliance archives worldwide.
Initial release: 1983

Frequently Asked Questions

Why convert SD2 to VOX?

SD2 is a professional niche format rarely supported outside Avid products. Converting to VOX makes sharing effortless.

What programs can open VOX?

Open VOX with Dialogic systems, SoX, Goldwave, telephony software. These applications provide full playback and editing support for the format.

How is audio fidelity handled during conversion?

The converter preserves maximum fidelity. If VOX is lossless, no data is discarded. Lossy codecs apply minimal perceptible compression.

How many SD2 files can I convert in one go?

Upload as many SD2 files as you need and convert them to VOX simultaneously. The batch feature handles multiple files efficiently.

Are my SD2 uploads kept private?

Yes. Uploaded SD2 files are deleted right after conversion, and the VOX output is removed from our servers within 24 hours automatically.