[LAU] questions about resampling - was - jack and the merging of soundcards

[Len Ovens]

On Fri, 21 Nov 2014, Simon Wise wrote:

> merging sound cards means either you can run both off the same clock, or one 
> is being re-sampled. Some soundcards can run using external clocks ... so 
> with appropriate cabling or settings very specific to your setup it is 
> possible to avoid resampling ... but most merging-into-one will involve 
> resampling, with or without advertising that this is the case, because it 
> works well.

Ok, so open question then. Does it make a difference to quality what the 
original rate is? For example: the direct card with no resample is a 48k, 
the second card will be resampled, is it better to be as close as possible 
to 48k or would starting at 96 (or whatever) work better?

In all this I would assume, stereo pair inputs should be kept to one card. 
Or a suround group for that matter. Or does the internal resample for 
filtering make that not an issue anyway?

One more... if a group of inputs that start synced are resampled, do they 
have a better post resample channel to channel sync that accross two 
intefaces with different sample rates before resampling? (this is sort of 
what the above questions are getting at though there amy be other issues 
as well)

In the end, most people are comparing these questions to analog with the 
idea that there is no phase shift in analog... I can see that two analog 
channels through two eqs with the same circuit, set the same way, will 
still likely have some phase shift between them. So is the channel 
differences caused by digital manipulation better than analog? The same? 
Worse?

--
Len Ovens
www.ovenwerks.net