VoxWare MetaSound Audio CoDec 1.6.0.17

VoxWare MetaSound Audio Codec 1.6.0.17 is the original Windows ACM decoder that handles those files, and at 641 KB it is one of the smallest codec installs you will ever run.

Here is the honest part you need to know upfront: VoxWare MetaSound has not been updated since July 2004.

There is no signed driver for modern Windows, no successor release, and no active maintainer.

The download still works for the narrow set of files it was built for - voice recordings, low-bitrate audiobooks, narration tracks, and educational CD content from the late 1990s and early 2000s - but for anything else, modern alternatives are a better path.

The rest of this page covers both routes.

What MetaSound Was Designed For

MetaSound is a speech-optimized codec. Where MP3 and WMA fall apart below 32 kbit/s, MetaSound was engineered to keep voice content intelligible at 2-16 kbit/s, which is why educational publishers, CD-ROM developers, and corporate training producers in the late 1990s embedded it in their multimedia projects.

Audio tracks that contain only voice - lectures, audiobooks, language lessons, voice memos - sound noticeably cleaner through MetaSound than through general-purpose music codecs at the same bitrate.

What it was never good at: music, complex soundtrack noise, multiple audio streams, or anything beyond simple monophonic speech. Even pushed up to 8-16 kbit/s, it remains a voice codec, not a music codec.

When You Actually Need It

You need VoxWare MetaSound in exactly one situation: you have an old media file - usually an AVI, WAV, or ASF container from before 2005 - and your media player throws an error mentioning "Audio Codec Tag 75" or "audio codec 75 is required".

That tag identifier is unique to MetaSound, and no modern codec replaces it directly because the format is proprietary and out of common use.

If you are not sure which codec your file actually needs, drop it into the Codec Finder - it reads the file header in your browser and tells you exactly which decoder is missing, without uploading anything.

For a guided walkthrough of common playback errors, the Codec Troubleshooter covers the most frequent issues step by step.

A complete list of Windows audio codec tag identifiers - including 45 for Sharp G.726, 55 and 85 for the Fraunhofer MPEG Layer-3 Decoder, and 2000 for AC3 Filter - is documented in the Audio Codec Tags reference.

The Modern Path: K-Lite + Codec Tweak Tool

For most users in 2026, the cleanest way to deal with a VoxWare-encoded file is not to install the standalone codec - it is to install the K-Lite Codec Pack and enable the bundled VoxWare entries through Codec Tweak Tool.

K-Lite ships with the Codec Tweak Tool included in every edition from Basic upward, and the tool lets you toggle over 200 individual codecs from a single window - including the VoxWare codec family.

This is the same workaround experienced users have been recommending for years.

One reviewer on this page (saintraa, 2011) summarized it plainly: install K-Lite, open Codec Tweak Tool, enable all Vox codecs in the codecs tree, and the audio works.

The advantage over installing VoxWare directly is that K-Lite also gives you LAV Filters for everything else - H.264, HEVC, AV1, MKV containers, modern audio formats - so a single install covers both your legacy file and the next dozen modern files you will encounter.

For the broadest legacy format coverage, the K-Lite Mega Codec Pack bundles the widest set of older codecs alongside encoding tools and additional rendering filters.

For most users, however, K-Lite Codec Pack Full is the sweet spot - enough format coverage to handle legacy files without the bulk of the Mega edition.

The Direct Install Path

If you only need to play one or two files and you do not want a full codec pack on your system, you can still install VoxWare MetaSound directly.

Be aware that this codec does not ship with a standard installer, and that is the source of nearly every problem people report in the reviews below.

The installation steps are:

1. Download the archive and extract it to a folder you can find again.
2. Locate the file with the .inf extension.
3. Right-click the .inf file and choose "Install" from the context menu.
4. If Windows warns that "The software you are installing for this hardware has not passed Windows Logo testing", click "Continue Anyway".
5. On Windows 7 and later, you may need to right-click and choose "Run as administrator" before the Install option appears.

On Windows 10 and Windows 11, driver signing enforcement is stricter than on the Windows XP era this codec was built for, and the .inf install method may simply fail silently. If that happens, fall back to the K-Lite + Codec Tweak Tool route above - it is more reliable on modern Windows.

Alternative: Convert the File Once and Move On

Sometimes the most efficient solution is not to install any codec - it is to open the file in a player with built-in decoding, then re-export it in a modern format you will never have trouble with again. VLC Media Player carries its own internal decoder stack and ignores Windows codec registrations entirely, which sidesteps the whole Audio Codec Tag system.

If VLC can play your file at all, use Media > Convert / Save to re-export it as MP3 or AAC, and the next playback works in every player. For high-quality MP3 encoding driven by the same engine VLC uses, the LAME MP3 Encoder is the reference choice.

For DirectShow-based playback after the codec is installed - the path Windows Media Player uses - MPC-HC is the most reliable player choice and ships as the default in K-Lite.

Browse Related Codecs

If you are working through a stack of old files with several missing decoders at once, the full Audio Codecs catalog covers every ACM and DirectShow audio codec listed on this site.

For modern desktop audio support unrelated to legacy codec tags, the Realtek HD Audio Codecs driver package handles the hardware side of Windows sound, and the Microsoft Fix It alternatives page covers the modern replacements for older Windows codec repair utilities.