TLDR: Is there a higher theoretical AAC quality level than VBR Constrained, 320-381kbps? I appreciate music in as high quality as possible, although I cannot be described as a true audiophile by any means for example, I value convenience about as high, if not slightly higher than sheer quality - I am an iTunes Match subscriber and I stream my music from it, even on my Mac. As you may know, if you have any lossless tracks in your collection, it automatically converts them to a 256 kbps AAC file, whether it is matched or uploaded. There is nothing inherently wrong with that, but at least for the tracks that are not available on iTunes, I would like to upload them in higher bitrates if the codec used is lossy, iTunes doesnt convert the file, regardless of the bitrate. At first, I used to rip all my CDs to 320 kbps AACs in iTunes. Later, I started using a great piece of software called Pro Audio Converter (highly recommended and available here: https://itunes.apple.com/us/app/pro-audio-converter/id445279797?mt=12 ) it has tons of these handy settings and the mode which seems to produce the highest bitrates and largest AAC file sizes is the VBR Constrained mode which keeps the bitrate between 320 and 381 kbps at all times. The files produced with this mode have nominally highest bitrates I could ever achieve. Since I discovered this mode, I have been ripping new CDs and also re-ripping some old ones (those that iTunes Match didnt find a match for; and I have tons of those) to this quality level. I know many of you will say that its a waste of space and effort, especially if the difference is virtually inaudible and if tons of my music is matched and only in iTunes Plus quality anyway. But I would like to ask is this really the highest theoretical quality I can get from AAC or can I still squeeze something more out of the format?