[LAU] (Ardour) How to get rid of delay when recording ?

[jonetsu at teksavvy.com]

On Sat, 13 Feb 2016 23:08:32 +0000
Harry van Haaren <harryhaaren at gmail.com> wrote:

> For curiosities sake, would you mind measuing the round-trip delay?
> (Assuming you have a loopback cable available and time :)
> I think you might be surprised... because I always am that its
> actually worse than we think, because I usually look at the software
> "theory" latency, instead of actually measuring :D

Thanks for the comments, much appreciated.  

I would very much like to measure before doing any modifications.  I
consider this as an investment for when the machine and OS will
eventually change and an audio setup will have to be done again.  On
the web page it is mentioned, and shown, that an input and output (in
this case from the mb audio interface, and USB) are not made to be
connected together and doing so could/can damage the card.  Then I have
to ask before doing anything: is it possible to simply use a plain
stereo RCA cable to connect the stereo out pair to the stereo in pair
of a 1010LT card ?

If so, then how is jdelay connected and told to measure these connected
ports ?  The man page mentions to connect the jdelay in and out
together and that's all.  I guess this connection is used as a
reference to measure the actual audio connections. The web page doe snot
mention any argument to jdelay. Will it detect which ports are
connected ?