Polycom EF2241 Matrix Mixer, Echo Canceller Reference, Residual Echo, Room Audio Sounds Choppy

TROUBLESHOOTING

MATRIX MIXER

Don’t hear output • Make sure the output is not muted.

•Check that the input you’re expecting to hear is included in the output that you’re listening to.

ECHO CANCELLER REFERENCE

Room Audio Sounds Choppy

If you hear the local room’s audio from the loudspeakers and it sounds choppy, you may have included the room’s microphones in the echo canceller reference. The echo canceller reference should NOT include the local room’s microphones -- it should only contain the remote end’s audio and program audio. You can still add the local room’s microphones to the local output with the matrix, but do not add them to the echo canceller reference. For more specific guidelines on what to include in your echo canceller reference, see “Build Your Echo Canceller Reference” on page 17.

RESIDUAL ECHO

Reverberation vs. Acoustic Echo

You may hear residual echo if system levels are not set properly. Improper level set- tings anywhere in the audio path can introduce nonlinearities that hamper the opera- tion of the EF2241. If you hear residual echo, one of the following conditions may be causing the problem.

Do not confuse the residual echo of remote speech with the reverberation of local speech. Reverberation of local speech is caused when the speech signal arrives at the microphone via several paths (the direct path and multiple reflections from surfaces in the room). This is a local room phenomenon that gives the talker’s voice a hollow or resonant sound (as heard at the remote end).

VORTEX EF2241 Reference Manual 38 Technical Support: 800.932.2774