[PD] latency issue

[Justin Glenn Smith]

babsyco babsyco wrote:
> Thanks guys, but the latency is still around 20ms when I don't use the soundcard (I just tried it with the built in mic-that's the same as jack for all intensive purposes, right?). Any other suggestions as to how I can get it lower? I really wanna use it for live performance.

No. That is not the same as using it with jack, at least it would not be on a Linux
system, I could be wrong about mac, but from what I know nothing compares to using
jack, performance wise. Another issue could be externals, try measuring the performance
without any externals loaded and see if one of the ones you are using is causing latency.

Also, many commercial audio apps misreport latency; for example a large number, if
not most of them, report only the latency introduced by the app itself, which is in
their case actually cumulative with the latency introduced with the OS drivers and the
latency inherant in the DAC / ADC of the card itself. With jack, at least, you are getting
a much more accurate picture of the latency.

This is based on reports of users who have measured their latency and compared it with latencies
reported by jack and by mainstream nonfree software; there are actually applications to help you
measure the latency you are getting by looping back a coded signal between the DAC/ADC and
measuring the phase difference, this could actually be coded in PD and would be an
interesting exercise come to think of it.