[LAU] Value of low-latency in audio?

[Mark Knecht]

On Sat, Dec 12, 2009 at 12:31 AM, david <gnome at hawaii.rr.com> wrote:
> Just wondering. Without an RT kernel here, my 2 laptops seem to run my
> simple audio needs pretty well at 64msec latency. At least, it's never
> bothered my playing along with computer-generated audio.
>
> I don't do any heavy-duty audio work here. Once I tried Jackrack, put
> one effect in it (that worked) or one amplifer (that worked) but trying
> to use both didn't. But I don't know if that had so much to do with
> latency or lack of RT kernel as with a smallish amount of memory and an
> underpowered processor driving the whole thing. Now that I''ve upgraded
> the memory on both laptops, perhaps it would work? On musicbox, with
> 512MB, using a single good quality (larger) soundfont was enough to
> cause problems. With 768MB in it, it works without problems.
>
> I see people on the list running much lower latencies than 64msec, and
> seemingly trying to get even lower ...
>
> So, just wondering.
>
> --
> David
> gnome at hawaii.rr.com
> authenticity, honesty, community

Hi David,
   As others has stated you'll have trouble with live recording if
you're monitoring through your recording app, but I'll submit you
wouldn't have *ANY* trouble at all *IF* if you use hardware monitoring
and mix your recorded signal back into a headphone mix without going
through Alsa. As long as the delay in the headphone path is 'natural'
- ie. - the hardware path is near zero - then that will sound fine.
However the recorded signal will be quite late in it's recorded track
so you'd have to nudge that back into position. You can do this with
vocals using a small external mixer and sending your mic preamp to
both the recording app as well as the mixer and then not sending the
recorded vocal out on a send to the headphone mix.

   Working around latency isn't impossible. It's not fun but it
doesn't have to get in the way. I've recorded band live and used 128mS
delay since they aren't listening to what I record and large latency
gives me more protection against xruns.

Hope this helps,
Mark