[LAU] [LAD] Document on using Jack Apps

[Paul Davis]

On Tue, Aug 3, 2010 at 7:02 AM, Jean-Yves Poilleux <jypllx at gmail.com> wrote:
> Hi
> Actually, there is some info that can be found here and there on some forums
> (see below)
> JDelay is, from what I've understood, a command-line tool that allows you to
> determine your sound card latency.
> #1 : start jack
> #2 : type jdelay in a terminal
> #3 : patch connections in jack : input -> jdelay, jdelay -> output, you
> should get a tone in your speakers

this is totally and utterly wrong. you have to patch the PHYSICAL
output connector of your soundcard to the PHYSICAL input of your
soundcard.

> #4 : latency is calculated, using phase difference between input and output
> #5 : in the terminal, the latency is printed in msec.
> It never worked on my soundcard, "signal below threshold"

yes, because jdelay is sending a signal out of the soundcard expecting
it to come back, but you have not connected it so that it can.