AAC+ Settings to beter broadcast

[cronos3gr]

if can tell me someone about settings for broadcast with ACC+ in Shoutcast...what is the better bitrate for ''more listeners'' if my ''Upload'' bandwidth is 256...in stereo or mono...i try something , but i can't see up to 16...16 is the most good to me?..or more down ,to have more listeners (how many listeners will have in 16?)........write me some answers please....thank you..