I think that the only way to get the so claimed 2.9 msec latency is to
 reduce to 64 the numbers of frames, but I don't know if is it possible
 with my sound card and if my actual limit of 512 is due misconfiguration
 or is the real limit for the Audigy.
 Anyone want correct, suggest, help me is welcome. 
 The problem is mostly the audigy but also that jack is not designed for
 badly designed hardware like usb audio devices.  
 
Antonio,
is it the USB based Audigy you are talking about?
If so, forget everything I said ;)
/Robert