fix defaultToSpeaker / mixWithOthers mixup.
fix defaultToSpeaker / mixWithOthers mixup.

eljeff/AudioKit,audiokit/AudioKit,eljeff/AudioKit,eljeff/AudioKit,eljeff/AudioKit,adamnemecek/AudioKit,audiokit/AudioKit,adamnemecek/AudioKit,audiokit/AudioKit,adamnemecek/AudioKit,adamnemecek/AudioKit,audiokit/AudioKit