Architectures of numbers of microphones and their positioning in a device for sound source direction estimation and source separation are presented. The directions of sources are front, back, left, right, top, and bottom of the device, and can be determined by amplitude and phase differences of microphone signals with proper microphone positioning. The source separation is to separate the sound coming from different directions from the mix of sources in microphone signals. This can be done with blind source separation (BSS), independent component analysis (ICA), and beamforming (BF) technologies. The device can perform many kinds of audio enhancements for the device. For example, it can perform noise reduction for communications; it can choose a source from a desired direction to perform speech recognition; and it can correct sound perceiving directions in microphones and generate desired sound images like stereo audio output. In addition, with source separation, 2.1, 5.1, 7.1, and other audio encoding and surround sound effects can be straightforward.