Best compression settings for AAC?

[bieneleve]

I use XLD to compress FLAC files on my Mac. I use AAC to compress them but it offers me four choices: CBR (constant), ABR (average), VBR Constrained, or True VBR. With the first three options I also have the option to use "HE-AAC". The other settings are self-explanatory. Which of these modes will produce the highest quality?

 

[dkane360]

I would use constant at the highest bit rate possible

 

[its phillip]

I'm not experienced with AAC, but I'd go with whichever was the highest quality VBR option.