Re: Re [AG-TECH] Tabletop-Room mic with integrated echo canceling

[Michael Braitmaier <braitmaier@xxxxxxx>]

Hi Chris!

Christoph Willing schrieb:
> On 21/06/2007, at 7:03 AM, Ed Brannin wrote:
>
> > On 6/20/07, Michael Braitmaier <braitmaier@xxxxxxx > wrote:
> > Hi everyone!
> >
> > [snip]
> > I decided for a solution which is in the beginning a bit more work. I
> > ended up buying the following DSP-EchoCanceler-Board
> >
> > http://www.phnxaudio.com/Default.aspx?tabid=75
> >
> > Basically it does the same as their PCI-Card which however only fits in
> > Desktop-PCs. (see link for information: 
> > http://www.accessgrid.org/node/116)
> >
> > We've had a SOHO card for a while, but never installed it until 
> > today.  Sadly, it performed just like the hardware listing said:
>
>
> The performance description in that particular hardware listing is 
> open to wide interpretation -
>     "neither local nor remote sites noticed any audible difference 
> from that produced by our standard setup"
> since it depends the status of the "standard setup".
>
> Perhaps the author could elaborate on whether the standard setup 
> includes working echo cancellation, or has none.
>
>
> chris

My experience with the DSP version was good so far, however it needed 1 
upto 2  seconds to adapt to new speaker levels, or changed distances 
between mic and speaker.
Unfortuanetly the production environment I used it recently, consisted 
of an old palazzo in Bologna/Italy which didn't provide the best 
accoustic environment due to high rooms with
half-sphere roof charactersistic, which itself already caused a certain 
echo or hall effect. So this was not the best opportunity to completely 
test echo cancelation.
However we plan to continue the use of the device and I hopefully can 
give an update on its echo canceling capability in the future, when we 
have more results.
Our intial tests in the office over AG with a room based node however 
were  fine.

Michael
> > It doesn't work.  At least, not in a small, square room with 
> > wall-mounted speakers.  We played a video on the computer, then 
> > watched Rat's talk levels match William Shatner's voice.
> >
> > From your email, it's hard to tell if you're using their DSP board, 
> > or if you've just bought one and still need to put it together.  
> > Either way, I'd like to know: does your way of doing it actually 
> > cancel any echo?
> >
> > Thanks,
> > -Ed Brannin @ RIT
> > edbrannin@xxxxxxxxx
> >
> > PS: So far, we've been most pleased with an Accumic PC.  We've also 
> > had mixed results from chaining together several of Phoenix Audio's 
> > Duet Executive microphones, but the seem to work in our current 
> > arrangement.
>
>
> Christoph Willing                       +61 7 3365 8350
> QCIF Access Grid Manager
> University of Queensland


--
------------------
Dipl.-Inf. Michael Braitmaier
HLRS - Visualization / Video Conferencing
University of Stuttgart
Germany
Phone: ++49 711 685 65996
Fax  : ++49 711 682 357
Website: http://www.hlrs.de/people/braitmaier/