AAC format sample rate questions

When I render AAC files from a 96k montage, the AAC files have a sample rate of 96k

When I convert 96k WAV files to AAC using Sonnox Pro-Codec Manager, the files are a sample rate of 44.1k, I see no option for sample rate.

Is there a way for Wavelab to render 44.1k AAC files from a 96 montage without using the Crystal Resampler? I wasn’t aware that AAC files could have a sample rate of 96k so I was expecting my rendered AAC files from Wavelab to be 44.1k.

Does this mean that the Sonnox Pro-Codec Manager is doing some sample rate conversion when making the AAC files?

I’m trying to render files that will be exactly like the AAC files that would be distributed by the iTunes Store which appear to be 44.1k VBR AAC files. I was thinking that the sample rate conversion would be part of the AAC conversion process.

Which is more true. the Sonnox Pro-Codec Manager, or Wavelab when it comes to making AAC files?

The AAC codec might change the sample rate automatically, using its own sample rate converter.

Supposedly the Sonnox uses the Apple codec on Mac, just like Apple does when they make their files. I can only assume the Sonnox also uses the Apple SRC as Apple does.
But the most sure way to ensure they’re exactly as the iTunes Store files is to make 96k 24bit wav files in Wavelab and convert them either in the Apple MFiT droplet, or convert them with the iTunes Plus setting in iTunes on Mac (iTunes can handle the 24 bit just like the droplet). On Mac both the droplet and iTunes itself use exactly the same chain (including the Apple codec and Apple SRC) so the result will be exactly as the iTunes store files. For non-MFiT, just make 44.1 16bit wav your usual way and convert with the droplet or iTunes itself.

Thanks for the insight.

I wonder if Wavelab could implement AAC encoding like the Sonnox Pro-Codec can, using the exact same encoding that is done in Mastered For iTunes, including the sample rate conversion when the source audio is higher than 44.1k.

It would be nice to render MFiT simulated files direct from a Wavelab montage that is higher than 44.1k sample rate.

Seems like it could be done as Sonnox has done on Mac incorporating the afconvert commands already built into the OS and published in the Apple “mastered for iTunes” PDF on the page linked below. And done on Windows with the QAAC tools (which Sonnox didn’t do). It might be a lot of work to program in, but it would make Wavelab unique.
https://www.apple.com/itunes/mastered-for-itunes/
https://sites.google.com/site/qaacpage/

I guess it would have to be only on the Mac version of Wavelab, but it certainly would be helpful if Wavelab could render AAC files using the iTunes+ format that the Sonnox can encode to.

I’ve had a few cases where clients want AAC files that will be exactly like the AAC files distributed in iTunes Store.

When working in Wavelab at sample rates higher than 44.1k (as MFiT releases usually are), the only real way to do this is using the Sonnox Pro-Codec Manager to convert WAV to true iTunes+ AAC format which is a time consuming extra step.