VOC to GSRT Converter

Create Grandstream ring tones from Sound Blaster VOC

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VoIP Ringtone Ready

Convert Sound Blaster VOC sound effects into GSRT ringtones — ready to deploy directly on Grandstream VoIP phones.

Custom Phone Audio

Personalize your Grandstream phones with unique ringtones from your VOC collection — a distinctive touch for your VoIP setup.

Cloud-Based Tool

No Grandstream configuration tools needed. Convert VOC to GSRT online in seconds.

How to convert VOC to GSRT

1

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

2

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

3

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

About formats

VOC (Creative Voice) is a digital audio container developed by Creative Technology and introduced alongside the original Sound Blaster card in 1989. It served as the native audio format for the Sound Blaster family during the DOS era, when Creative's hardware dominated PC audio. VOC files are block-based: each file consists of typed data blocks that can carry 8-bit unsigned PCM, 4-bit and 2.6-bit Creative ADPCM, 16-bit signed PCM, as well as A-law and mu-law encoded audio. This block structure also supports silence intervals, repeat loops, and marker points, giving game developers fine-grained control over sound playback. A notable advantage was hardware-level decoding — Sound Blaster cards could play VOC data directly via DMA transfer, freeing the CPU for other tasks in an era when processor cycles were precious. The format saw extensive use in DOS games from id Software, Sierra, and LucasArts. With the rise of Windows and the WAV format, VOC gradually fell out of mainstream use, yet it remains important for retro gaming preservation and for anyone working with vintage PC audio archives.
Initial release: 1989
GSRT is a purpose-built ringtone format developed by Grandstream Networks for its line of IP phones and VoIP endpoint devices. Each file begins with a fixed-size header identifying sample rate (typically 8 kHz or 16 kHz), bit depth, and payload length, followed by PCM or mu-law encoded audio data optimized for the small speakers found in desk phones. The design prioritizes minimal decode complexity — Grandstream handsets run on embedded processors with limited memory, so the format avoids transform stages or complex bitstream parsing. Ringtones are usually provisioned through a web management interface or a centralized configuration server, letting IT administrators push branded audio to an entire fleet of phones at once. Although GSRT occupies a narrow niche within enterprise VoIP telephony, its straightforward binary layout means conversion tools can map the payload directly to WAV with minimal effort. Key advantages include rock-solid playback reliability on Grandstream hardware, negligible latency from file read to speaker output, and seamless integration with the provisioning ecosystem for company-wide ringtone deployment.
Initial release: 2002

Frequently Asked Questions

Why convert VOC to GSRT?

GSRT is the ringtone format for Grandstream VoIP phones. Converting VOC lets you create custom rings and alerts for Grandstream devices.

What can open GSRT files?

Grandstream VoIP phones and gateways play GSRT natively. The format is specific to Grandstream — convert to WAV for general use.

What is GSRT?

GSRT is the custom ringtone format for Grandstream VoIP phones and ATA devices. It stores audio clips formatted for these endpoints.

Can only Grandstream devices use GSRT?

GSRT is proprietary to Grandstream. Other VoIP brands use different ringtone formats — GSRT will not work on non-Grandstream hardware.

What sample rate does Grandstream expect?

Most Grandstream phones accept 8 kHz, 16-bit mono ringtones. Check your specific phone model for exact requirements.