[AG-TECH] USB mics for Mac OS X /Intel ????

Fred Dech fdech at uchicago.edu
Thu Nov 15 09:30:09 CST 2007

interestingly, i've had the opposite experience with RAT and Mac audio on
multiple machines and i know there are other people aware of problems and
who have also not been able to get acceptable audio using RAT on OS-X intel.
i currently have 3.1.0b1 and 3.1.0b2 on a couple different OS-X intel platforms
but do not use audio on either.

the symptoms i and others have had and still have with the UCL RAT are:
1.  delayed audio receive and sometimes send as well.  at the mac intel
    client, audio is often between 1/2 and 1 second out of sync with VIC.
    we've also seen sent audio from the Mac delayed with respect to VIC on
    other non-mac receiving clients in venue tests.  yes, we are running the
    intel build of RAT.
2.  predictably, with the Chat50 for instance, received audio is not just
    delayed, audio becomes garbled and unintelligible.  this garbled audio
    has also been experienced on remote clients who are sent audio from
    the mac ag node.  sometimes killing RAT and restarting it temporarily
    clears up the audio, but it soon begins to degenerate again.

we've tested RAT with OS-X intel audio extensively and have not found
it to be usable.  we have two nodes with a Mac display machine and a separate
video capture machine.  we run RAT on the capture machines.  if we could get
usable audio we'd definitely be running.  our testing was done using headsets,
Chat50, AccuMic PC, and XAP400.

what i find very confusing is that there seem to be two distinct groups
of uses; those who experience acceptable AG audio with OS-X intel clients
and those who experience unacceptable AG audio with OS-X intel clients.


  Fred Dech   fdech at uchicago.edu
  University of Chicago Dept. of Surgery
  Ph: (773) 834-8359, Fax: (773) 834-8400

On Thu, Nov 15, 2007 at 10:09AM, Nathan Gardiner wrote:
> Likewise, we use the Chat 50 and 150 and they work fine on MacOS X, Win
> XP, and 95% fine on Linux.
> Regards,
> ------------------------------------------------------------------------
> -
> Nathan Gardiner
> Human Interface Technology Lab NZ (HIT Lab NZ)
> Room 110, Old Maths Building, University of Canterbury
> DDI: +64 3 364 3072, Cell: +64 21 163 2956
> -----Original Message-----
> From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On
> Behalf Of Bob Riddle
> Sent: Thursday, 15 November 2007 6:43 a.m.
> To: gurcharan khanna
> Cc: ag-tech at mcs.anl.gov
> Subject: Re: [AG-TECH] USB mics for Mac OS X /Intel ????
> Chat 50 and Chat 150 work great - just plug them in.  I prefer the Chat
> 150 when multiple speakers are in the room.
> gurcharan khanna wrote:
> > hi,
> >
> > what's the latest on using echo cancelling mics or headsets for new 
> > Mac laptops?
> > anyone have any direct experience?
> >
> > thanks,
> >
> > -gurcharan
> >
> -- 
> Bob Riddle (bdr @ umich.edu)            Enabling Technologies
> University of Michigan Medical School   1301 Catherine Street
> M4101 MSB1 - 6024                       Ann Arbor, Michigan  48109-0624
> Phone: (734) 330-2533			Office: (734) 615-9258
> "Never argue, repeat your assertion"  Robert Owen, from the "The Book of
> Bob"

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