R u sure your PCaudio mixer settings are correct?
----- Original Message ----- From: "Peter DeSantis" <pe...@jumbovision.com.au> To: <ag-t...@mcs.anl.gov> Sent: Tuesday, April 26, 2005 9:46 AM Subject: [AG-TECH] unexplainable audio feedback problem on XP with RAT > Hi, > > i have an audio problem on an access grid, if anyone can please help > > This is a 3 pc access grid, that works fine, except for an unresolvable > audio feedback problem. > > The audio capture computer is > > Intel P4 3.2Ghz > Xp pro SP2 > Soundblaster Audigy2 soundcard. > Vortex EF4220 echo canceler. > > Basicly, we set up the grid, ran all the software, adjusted the > echocanceer and everything was fine for 3 days. We had regular test > conversations with other users and except for a minor feedback and echo > issue that were quickly fixed everything was perfect as far as we could > see. Basically for 3 days audio seem totaly great. > > Normaly the pcs are left on, then one morning we noticed the audio capture > computer had reset for some reason and was sitting at the bios screen. We > resarted it and all seemed fine untill we ran the AG software for a > session. > > Basicly the problem is there is now this intense unexplained feedback loop > occuring, where before there was none. Using the echo canceler software we > can monitor the audio levels in the echo canceler and the diagnostic > screens show maxed out levels of internal audio running through it. > Previously the levels were normal. > > When we restart the computer and echo canceler the internal audio levels > look normal. Then when we start the AG software and the RAT runs, we can > see on the dignostic screen the internal audio levels get maxed out, BUT > no feedback is audiable in the room through the hardware and no problem > noise is audiable to the other end. But then if we exit the RAT client the > feedback screams out the speakers into the room and we have to shut the > amp off to quiet it, to prevent damage. this is the strange thing that the > feed back only comes out the speakers when the rat is shut off, and we > also get it when the RAT shuts down briefly to change from one room to the > next. > > For 3 days the system worked fine then suddenly this started and i cant > figure whats causing it, as every setting on the echo cancler and the > sound card is the same as before. We made sure the "record without > monitoring" option on the sound card was activated as this was the initial > casue of feedback that stoped when we activated it. I am totaly > flabergasted as to what the casue might be. Its almost as if the RAT > client is bridging some internal soundcard buffer when it runs, causing > audio sources to be mixed and casuing the problem. As i said, it all ran > fine for 3 days before this quirk started. > > > Has anyone had anything similar ? It occurs to me perhaps the best thing > to try might be to reinstall XP and AG toolkit from scratch. > > Any help appreciated. > > Thanks > > Peter DeSantis > pe...@jumbovision.com.au > Jumbo Vision International Pty Ltd > Unit 2 ,1 Aitken Way > Kewdale WA 6105 > Australia > > Tel: 61 8 9353 6200 > Fax: 61 8 9353 6211 > > > > Thanks > > Peter DeSantis > pe...@jumbovision.com.au > Jumbo Vision International Pty Ltd > Unit 2 ,1 Aitken Way > Kewdale WA 6105 > Australia > > Tel: 61 8 9353 6200 > Fax: 61 8 9353 6211 > >
