A method and apparatus of audio processing is described. An audio processor may receive a multi-channel audio signal. In a first mode of operation, an audio processor may output a first audio signal on a first multi-channel audio output and a second audio signal on a second multi-channel audio output. In a second mode of operation, the audio processor may output a third audio signal on the first multi-channel audio output and a sub-woofer audio signal on at least one channel of the second multi-channel output.