Ah, perhaps a clue:
OK. Is 'dmix' already something which all ALSA streams go through? Or is there a specific way to require it?2. Theory #2 is the better because it accounts for the fact that it was working pretty well: might the ALSA2Jack plugin have trouble handling multiple streams at once? If so, is there a streams-mixing plugin I can use before ALSA2Jack, to make this work better?no, the only stream mixer in ALSA is dmix.