I have a sound recording roughly 40 minutes long at 24bit 96khz.

I've found that after trimming off about 40 seconds total of leading and trailing silence (well, quiet background hiss to be precise) from the original WAV and encoding to flac, the resulting file size is 40MB larger than the original recording encoded to flac!

Why would this happen?

  • 2
    You trimmed off the easy bits (-:
    – Jim Mack
    May 12, 2015 at 17:22
  • I have similar experiences, like a FLAC of a MONO version of a stereo file to be bigger than the FLAC of the native stereo. Makes no sense to me.
    – jcea
    May 20, 2015 at 13:21
  • FYI the same kind of thing happens with mp3s
    – JSmith
    Feb 6, 2016 at 16:45

1 Answer 1


Although FLAC encoding is always lossless, it still offers different compression levels to choose a tradeoff between size and decoding speed.

So, the unexpected difference in size that you noticed may come from different compression levels between the files.

Try to re-encode the cropped file with maximum compression level (8) and compare sizes again.

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