Embodiments are directed towards providing acoustic echo cancellation in a closely-coupled microphone/speaker system. A speaker may produce an audible signal from a reference signal, which may be captured with a microphone. Full band cancellation (FBC) may modify the captured signal to suppress an echo of the reference signal caused by a direct acoustic path between the microphone and speaker. FBC may include a fixed filter and an adaptive filter. The fixed filter may modify the captured signal based on the reference signal. The adaptive filter may automatically adapt based on the captured signal and the reference signal. If a comparison of a performance of the adaptive filter and the fixed filter is above a threshold, then the fixed filter may be updated based on the adaptive filter. Subband acoustic echo cancellation may generate an output signal that suppresses residual echoes of the reference signal based on the modified signal.