Today I downloaded a soundtrack composed of 19 tracks. Their format is FLAC (24bit depth and 96kHz sampling).

In order to add them to my iTunes library and eventually to my iPod, I converted the files to ALAC (24 bit 48kHz) which is the maximum my 7th gen iPod classic can handle.

Problem is, iTunes won't let me import those converted files into the library. I noticed those files have 6 audio channels. I think that is the problem, and I've started looking for an answer. Internet wasn't very clear, unfortunately.

My question is : is there a way to import those files to iTunes? Is there a way to down mix the files to 2 channel audio or similar, so iTunes can handle them?

(I hope such a conversion wouldn't distort the audio) I usually use XLD to convert my audio files, and there's no option for down mixing.

  • Very confused question... Points: 5.1 is 6 channels; mp4 is not an audio format; down-mixing 5.1 to iPod stereo you may as well throw out the silly sample rates & just go for 128bit 48KHz AAC, because the DACs won't show up much above that unless you're listening on high-end monitors in total silence. [& only 48 to save the odd floating point issues of dropping to 44.1]
    – Tetsujin
    Apr 19, 2018 at 18:28
  • Well, I've just asked if apple had devised a way to down mix 6 channel audio to stereo(ffmpeg does it really well, but you have to use the terminal; there is no appreciable distortion, the sound is pretty good). I'm not an engineer so I may have made some mistakes while explaining my question, for that I apologise. About the mp4, I've written it because I had read someone on the internet who'd solved a similar problem converting the file to mp4, but I wasn't sure about that. I have a really good hi-fi system, and the differences between lossy and lossless are perceivable.
    – Luke
    Apr 20, 2018 at 9:59
  • I have to use iTunes because it's the only way I can put songs into my iPod, i don't use it with my hi-fi system. I just wanted to put those songs into my iPod, and preserve their quality in the process.
    – Luke
    Apr 20, 2018 at 10:01

2 Answers 2


I sorted it out! You can down mix the audio files from 6channel to 2 channel using ffmpeg (you have to use the terminal, though). The down mixing process is quick and there are no perceivable distortions in the audio.

  • Sorry, question is confused, answer doesn't help at all.
    – Tetsujin
    Apr 19, 2018 at 18:20
  • Question : how to put 6 channel audio files on iTunes? has apple devised a way (through iTunes or any other app) to "convert" or better, down mix, the files, so iTunes can open them? (And avoid audio distortions in the process) Answer : ffmpeg does that, but it works through the terminal. you have to input commands through the terminal
    – Luke
    Apr 20, 2018 at 10:07

I've just found it is actually possible to get multichannel file into iTunes, but AFAIK iTunes won't actually play it back in anything other than stereo. (Still useful if your library is used outside by other software which can play multichannel.)

I set my encoder to:

  • Profile: MPEG-4 AAC LC
  • Gapless: iTunSMPB
    • Method: CBR
    • Bitrate: 960k
      (Note: For a 6ch file, I suppose this is equivalent to stereo 320k. When I set it to 6000k, which was close to my source file, I got a roughly 1320k file as a result, so perhaps AAC can't push much higher than that.)

And my decoder to:

  • Bit Depth: Original
  • Sampling Rate: 44100
    (Note: It's probably best to match this to whatever the original file is. I guess you can set it to anything up to the max your iTunes is configured to play, but obviously going higher than the original file is likely pointless.)
  • Channels: Original

This allowed me to convert a 6ch WAV to a 6ch AAC m4a file. Playing the file in VLC and looking at the Codec Info viewer verified the 6 channels were present (as did just listening to the file in VLC). I could import and tag the new .m4a file in iTunes just like any other file, but like I said, it only plays in stereo (down-mixed, I think, rather than losing the 4 extra channels).

I used TAudioConverter (more info, or download here), which is Windows only unfortunately, but there's likely another similar program for Mac. I imagine anything based on the fdkaac encoder, or even ffmpeg, can probably do it.

Oh, and if you do decide to use TAudioConverter for this, you might run into a minor issue/bug which results in a few error popups when you start the program which claim "Bass.dll" is missing. Accept/close them all and, once they stop popping up, just launch the program for a second time; it will load properly, then


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