A state of audio/electrical nirvana in which all alternating current waveforms (such as an audio signal) are on the same half of the positive/negative waveform. For example, an audio signal chain is said to be "in phase" when a positive pressure on a microphone produces a positive audio waveform which passes through a mixing desk with a positive audio waveform, and is thus bussed to a loudspeaker which produces a positive pressure. Can also be termed "Absolute Phase" or "Absolute Polarity". The term can also apply to adjacent microphones and their need to be the same polarity with respect to each other, or to adjacent loudspeakers and their need to be the same polarity with respect to each other. Two in-phase loudspeakers, barring positional constraints, that are fed the same audio signal will produce a constructive waveform which will be cumulatively louder in amplitude than if only one speaker was operational. Conversely, if two loudspeakers are wired with one wired 180 out-of-phase with respect to the other, the two waveforms will destructively interfere, and, barring positional constraints, the two waveforms would cancel out.