Yamaha MY4AEC 4-Channel Echo Cancellation Card (for Yamaha DME-N)The MY4 AEC card provides 4 channels of acoustic echo cancellation for remote conferencing using Yamaha's DME24N and DME64N digital mixing engines. As well as the echo cancellation function, the MY4 AEC card also offers a noise reduction function which removes steady state background noise such as air conditioning and projector fans etc. The card also has a feedback suppressor with 42 notch filters per channel to aid the suppression of feedback in PA