I don't believe I've seen this discussed. I'm pretty convinced that I can't hear anything above 16Khz, so I've been using APS -Y with pretty good results.

I'm curious now. Would be any advantage in using --alt-presets extreme -Y. Would I get any better quality in the range that I can hear, or is most of the advantage in extreme in the over 16Khz range?

I've tried this on a couple of samples and the bitrate only increased slightly over APS -Y.

I might like to use this instead of APS -Y if there is any benefit. My goal is to get the best possible quality I can in the range under 16Khz, with reasonable file size.

Any thoughts?

Try some abx tests and find out

Heck, I doubt if I could ABX CBR128. But I would still like to know from a technical standpoint.

Edit: OK, I could ABX a CBR128 with "Fatboy". That's pretty easy though.

I'd personally use --alt-preset standard -Z -Y rather than --alt-preset extreme -Y.

I think this all is blasphemy!