Re: [LAU] JACK with many soundcards

Am Donnerstag, 31. Juli 2008 schrieb Adrien DANIEL:
> On Thu, Jul 31, 2008 at 1:27 PM, Arnold Krille <arnold@email-addr-hidden> wrote:
> > Apart from the fact that there are ways of doing this in software (with
> > all the latency and uncertainty that arises there), you should *please*
> > look at the archives of this list and find out why it is nearly
> > impossible to do what you are thinking of.
> > In short: You definitely need to get the clocks of the converters in
> > sync. And you should also get the interrupts in sync.
> I am aware of these sync issues and I mentioned that in my second
> post, however I read somewhere that it is possible to do this in
> software with, as you said, some uncertainty. Of course, I voluntarily
> left apart hardware sync, since it concerns expensive soundcards.

But for making music with (real) instruments these are the important factors.
Of course you can add jitter-buffers to sync all the input- and
output-soundcards in software. But this adds a lot of latency. Something like
syncing two VoIP/Mobile phones with their sometimes horrible latency (which
you can hear when the echo-cancellation doesn't work correctly). And then try
to play non-experimental, non-electronic music about that...

> Anyway, in my opinion, the idea to provide a *high quality* guitar
> (including a *high quality* ADC) that you could easily plug into your
> computer to play music on a conventionnal hi-fi system is not so odd,
> commercially speaking. Keeping this in mind, I was simply wondering
> the extent to which it was possible to generalize this to several
> instruments (especially in JACK), again because it does not require
> any additional sound device or guitar amp.

Well, it requires additional devices: you do want to hear something. At least
the recording-engineer wants to hear what is on (digital) tape.
So you really have to sync all the devices by an external word-clock. Again:
firewire has a global bus-clock which devices (can) use to sync with so that
all devices on the bus have the same word-clock.

Arnold

PS: No need to CC me, I am subscribed...

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