6 March 2026 | 6 min read
What a WAV metadata editor actually edits
A WAV is not just samples. It carries chunks of text and timing that decide whether your file syncs, sorts and searches, or just plays.
Open a WAV in a hex viewer and you will find the audio surrounded by labelled blocks called chunks. The fmt chunk describes the format, the data chunk holds samples, and everything a metadata editor touches lives in the chunks around them.
The bext chunk
Broadcast Wave adds bext: a description field, an originator, an originator reference, a date and time, and the time reference that carries timecode as a sample count from midnight. This is the chunk that makes sync by timecode possible.
- Description: free text, often scene, take and notes from the recorder.
- Originator: the device or company that made the file.
- TimeReference: start position in samples, converted to timecode by your tools.
The iXML chunk
iXML is a structured XML block, and it is where field recorders store the interesting details: project, scene, take, tape, note, circled status, and the TRACK_LIST with a name for each channel. When your editor shows Boom and Lav instead of Track 1 and Track 2, it is reading iXML.
ID3 and LIST INFO
Consumer tools sometimes write ID3 tags into WAV files, borrowed from MP3, or a LIST INFO chunk with artist and title. Professional audio tools largely ignore both. If your metadata seems to vanish between applications, this mismatch is usually why.
Reading before writing
Before you edit anything, see what is already there. The audio inspector on this site reads format, channel layout, embedded track names and the descriptive fields directly in the browser, with no upload, which is a fast way to audit a folder or check what a recorder actually wrote.
What survives a conversion
Converting a WAV to MP3 or AIFF discards most of this. Timecode and track names do not exist in MP3. Keep the BWF master, and treat compressed exports as disposable copies.