[LAD] jackd and usb hub

[Luis Garrido]

On Sat, Oct 9, 2010 at 2:55 AM, Geoff Beasley
<geoff at laughingboyrecords.com> wrote:
> until Clemens chimes in... is it your own kernel Luis ? looks like usb2
> device in usb1 port maybe? check your usb config in the kernel perhaps

Hi, Geoff, thanks for answering. Clemens is perhaps the ultimate USB
audio guru, but everyone else's experience in this issue is of course
valuable and appreciated.

I tried this on Ubuntu and Fedora Core stock kernels (no -rt patch).
On Ubuntu jackd simply failed with no clue about was going on;
Fedora's kernel at least supplied the message I quoted in the top
message (probably it has activated some debugging flag that Ubuntu's
doesn't.)

If it helps some (probably not, since all the hubs in the market will
be some kind of wrapper or another around the same Taiwanese chip),
the hub model is Manhattan 160612:

http://komputercenter.com/usb-gadgets-c-7/hub-usb-2-0-manhattan-160612-p-16

Has someone else here managed to successfully run jack over USB audio
through an external hub? It is probably not the best setup out there
latency-wise (how long does it actually take for a USB frame to pass
across a hub, anyway?), but may be worth considering if low latency is
not critical, providing in return integrated USB port protection and
perhaps some degree of power supply noise isolation (or yet another
noise source, you never know, but I'd hazard the guess that anything
that separates audio equipment from LCD inverters in laptops should be
a good thing.)

Cheers,

L