I have inherited a video conferencing project using a Wowza Media Server 3 backend along with a flash-based frontend. I have minimal action script experience. When the users are not wearing headphones, unless the user manually checks the "Reduce Echo" box in the flash settings dialog we have some serious echo problems. We are setting the setUseEchoSuppressionproperty (see below) which according to the official documentation should be enough, but it appears that echo suppression is only enabled if the user enables it manually. Am I misunderstanding the expected behavior? AM I doing something wrong? If I can't actually enable echo suppression programatically can I at least check to see if it is enabled and provide a warning? My current mic initialization code:

microphone = Microphone.getEnhancedMicrophone();
microphone.rate = 16;
microphone.codec = SoundCodec.SPEEX;
microphone.framesPerPacket = 1;
microphone.setSilenceLevel(0, -1);
var options:MicrophoneEnhancedOptions = microphone.enhancedOptions;
options.echoPath = 256;
options.mode = MicrophoneEnhancedMode.FULL_DUPLEX;
options.nonLinearProcessing = true;
microphone.enhancedOptions = options;

Furthermore, when we are using any browser except IE under windows 8.0/1, there is STILL some echo on the call. The transcoder plugin does seem to reduce the echo issue for one party (we only have one transcoder license at this point). Would buying more licenses be likely to improve quality for everyone?