Optimal stream.transcode-settings for AC3

[Hubert]

Dear experts,
a long time ago I set stream.transcode to *:mp3;320k because all my music was in mp3-format. Recently I recorded a concert via satellite radio which I saved as concert.ts. I converted it to AC3 448 kb, 48000 Hz and stored it in my library as concert.aac. MinimServer has no problem to stream this file but I'm not sure, if the old *:mp3 setting is optimal for aac-files too. Should I change the stream.transcode setting to get even better sound quality?