[AG-TECH] echo problems

[JB Gallagher]

Hello,

I'm at the ASCI Flash Center, and we just moved our node into a new
room. My audio setup uses a Gentner AP400, Match Maker 100, the audio pc
with the sound blaster 128 card, and the Genelec near range monitor.
These devices are plugged together in the manner specified in the AG
documentation under the "Configuration for Balanced Sound".  I have also
setup a preset with Audio Perfect Tools (probably have a somewhat old
version) that matches the AP400 preset #1 (For net and teleco bridge) as
specified on the ag documentation web sites.  Basically in this setup
remote sites here their own echo when I have the Audio Perfect Tools
software running and synced up with the Gentner. I can hear remote sites
very clearly and without any problems. If I shutdown the Audio Perfect
Tools software, turn the Gentner off and on, remote sites no longer hear
their own echo, but now remote sites cannot hear me when they talk, as
if things were working in half-duplex. In fact just double clicking on
the Audio Perfect Tools icon, and seeing the slapsh screen of the
application, remote sites report hearing echo immediately. So even
before I sync the software up with the Gentner, echo is heard at remote
sites, after syncing up the software with the Gentner, echo is still
heard, but the trasnmission and recieiving of audio on both ends is
full-duplex. Does this set of symptoms ring a bell for anybody or give
anybody any ideas? Also, once the Audio Perfect Tools software is
running, remote sites report the same quality of echo whether or not I
have the "Enable Echo Cancellation" box checked or not in the microphone
windows, by default I've had them checked, and then as remote sides
report hearing echo I've unchecked them with no discernable change
precieved in the echo by the remote sites. Any ideas or help will be
much appreciated.

Thanks,

Brad Gallagher
ASCI Flash Center
jbgallag at flash.uchicago.edu