WAV files smaller than the original on export

I am using Audacity to add metadata to already mastered tracks. I am using no other function other than to import a wav file, add metadata and the export the file. The files seem to be down sampled by approximately half. For example a file that was 77,684 KB on import was 38,930 KB on export.
I can’t seem to find an explanation for this and I thought someone here might help. Thanks in advance for any help or information.

You probably changed he bit-depth, but half is “unusual”.

As you may know there are 8 bits in a byte so for uncompressed files file size can be calculated as:
File Size = Sample Rate x (bit-depth/8) x number of channels x Playing time in seconds.

That doesn’t include metadata, but that’s not significant unless you add artwork.

For example, “CD quality” is 44,100Hz x (16-bits/8) x 2 Channels = 176K per second or about 10MB per minute.

The sample rate is shown as Project Rate in the lower left of the Audacity window. If you just open-import one file, that shouldn’t change.

But Audacity doesn’t “remember” the original bit depth so you have to choose that when you export.

I am using Audacity to add metadata to already mastered tracks. I am using no other function

Try [u]MP3Tag[/u]. It works with most audio formats, not just MP3 and it will add/edit metadata without touching the audio. And if you’re working on an album you can select and edit the common data for all of the tracks at once. And it can add album art, which Audacity doesn’t support.

But, note that metadata for WAV is not well-standardized or well-supported. All of the compressed formats are generally better for metadata. If you want lossless, FLAC (or ALAC for Apple) may be a better choice (if you can use it) and your files will be about half the size, without changing the quality.

You can check the original file format (or both formats) with [u]MediaInfoOnline[/u].

Thanks for your information. This Helped. I am helping a musician friend upload his music to a distributor. I realize that some distributors remove metadata when uploading to different streaming and download services, but I feel better sending them out with copyright information attached. I will give MP3Tag a try. Again, thank you for your time and information.

Bit-depth & sample-rate are in the header file, (the “format chunk”).
Erasing the user-contributed metadata, (artist, title, etc) will not remove the rate info, (as it is required to play the file).