Here Kai explains the three modes and how they are chosen.[1] --quote-- In '-B:auto' mode (which is the default), 'nonrt' is selected if there are no realtime inputs or outputs (/dev/dsp, alsa, rtnull). If there are rt objects and current process has root priviledges, 'rtlowlatency' is selected. And in other cases it's 'rt'. --quote-- Regards, Joel 1. http://eca.cx/ecasound-list/2001/10/0020.html -- Joel Roth