Another Amateur (Advice on a configuration)

[Mike Dickson]

  Hi!   I'm trying to set up a configuration to stream "karaoke" style 
audio (into SecondLife for a open mic performance).  I have jack running 
(and pulseaudio running through it) and have used IDJC successfully to 
stream.  I really haven't been able to use that to sing live because I 
get a small but very obvious delay in the vocals. I thought there must 
be a way to do software mixing similar to what you'd do in hardware: 
that is playing the karaoke track over headphones and adding my voice 
mixed down to one stream, then thats fed to IDJC.  If I have to I can 
pre-record the tracks though I'd really prefer a live setup if possible.

Can anyone offer any suggestions or pointers to howto's to set up a 
system for live performance like this?

Thanks!

Mike