In the past I’ve chosen I’ve often kept AC3 audio tracks thinking that their substantially higher bitrates made them better than the AAC tracks I compared them to. As I’ve since learned that AAC can be comparable to AC3 at a substantially lower bitrate, to have a means of comparing the two codecs, what would the AAC-equivalent bitrates be for 224kbps and 640kbps AC3?
Definitely needs some more testing as those numbers in the table look low to me. Archiving vs listening is a key point and storage is relatively cheap.
Listening on cheap Bluetooth headphones then you can get away with a low bitrate. If you are using better gear and/or music that has a lot of dynamic range and comes from strings (piano/classical/etc) then I would recommend 320 but your mileage may vary.
Listen, compare and decide. I have a library of about 110k tracks (musicbrainz-Picard is amazing) and I wish I had: