Re [AG-TECH] Tabletop-Room mic with integrated echo canceling
braitmaier at hlrs.de
Thu Jun 21 01:47:13 CDT 2007
Christoph Willing schrieb:
> On 21/06/2007, at 7:03 AM, Ed Brannin wrote:
>> On 6/20/07, Michael Braitmaier <braitmaier at hlrs.de > wrote:
>> Hi everyone!
>> I decided for a solution which is in the beginning a bit more work. I
>> ended up buying the following DSP-EchoCanceler-Board
>> Basically it does the same as their PCI-Card which however only fits in
>> Desktop-PCs. (see link for information:
>> 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.
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
>> 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?
>> -Ed Brannin @ RIT
>> edbrannin at gmail.com
>> 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
> Christoph Willing +61 7 3365 8350
> QCIF Access Grid Manager
> University of Queensland
Dipl.-Inf. Michael Braitmaier
HLRS - Visualization / Video Conferencing
University of Stuttgart
Phone: ++49 711 685 65996
Fax : ++49 711 682 357
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