Conversion WAV 192kHz/24bit to AIFF results in 192kHz/16bit

Hi bernhard178,

Welcome to Apple Support Communities. The information from Convert a song to a different file format with the Apple Music app or iTunes for Windows - Apple Support may help to explain this a bit. Particularly the following info from the 'Learn more' section.

"About compression

When you convert a song to certain compressed formats, some data might be lost. These compressed formats give you a much smaller file size, which lets you store more songs. But, the sound quality might not be as good as the original, uncompressed format.

You might not hear a difference between a compressed and uncompressed song. This can depend on the song, your speakers or headphones, or your music device.

If you compress a song and it loses data, you can't uncompress it to retrieve the data. If you convert a song from a compressed to an uncompressed format, its quality doesn't improve. The file only takes up more disk space. An example is when you convert a song in MP3 format (a compressed format) to AIFF (an uncompressed format). The song takes up much more space on your hard disk, but sounds the same as the compressed file. To take advantage of uncompressed formats, you should import songs in these formats."

All the best.

bernhard178 wrote:

I wanted to convert a WAV file in 192 kHz and 24 bit and 9.216 kBit/s with iTunes to AIFF. To my surprise I got an AIFF file with 192 kHz in 16 bit and 6.144 kBit/s. So the quality got worse!!!

Bernhard,

That is the Apple implementation of "lossless," ha ha.

The custom import settings for AIFF in Music do not allow any more than 16, and the "automatic" setting, which one might expect to maintain the sample size the same as the input, apparently downgrades 24 to 16.

If you want to provide feedback directly to Apple, use this link: Product Feedback - Apple

Hi,

I am puzzled by the answer. We are not talking about compression.

As you may have overlooked, WAV and AIFF are both uncompressed formats that can be expected to maintain quality when converted into each other.

So this seems to be a software bug, which unfortunately also exists in the current macOS release.

By when can I expect a fix?

Kind regards

As you may have overlooked, WAV and AIFF are both uncompressed formats that can be expected to maintain quality when converted into each other.

That is not a correct statement. They are both PCM-based encoding formats, which, depending on the sample rate and bit depth, may in fact yield a compressed output relative to the input.

I agree it is "expected" that the Automatic setting would maintain the bit depth of the input (24 in your case), but in the current implementation it did not. As suggested, you can submit feedback to Apple at the link provided.