The difference between mono and stereo Stereophonic sound systems have two or more separate audio signal channels where the signals have specific levels and phase relationships to each other. When reproduced through a suitable system there will be an apparent reproduction of the original sound source(s). Stereo can replicate the aural perspective and position of instruments within a band on stage. A listener's proximity to a speaker or speakers of a stereo system will often determine which instruments or tones they will hear. stereophonic - Of or used in a sound-reproduction system that uses two or more separate channels to give a more natural distribution of sound. Dictionary.com Stereo audio uses about twice the bandwidth of mono audio because of the two separate channels, with much of the information duplicated on both channels. MPEG audio can use conservative methods to maintain audio quality but reduce bandwidth by retaining only the audio information perceived as important to the stereo image. Mono or monophonic - A system where all the audio signals are mixed together and routed through a single audio channel, or Sound produced by a system in which one or more microphones feed a single signal-processing amplifier whose output is coupled to one or more loudspeakers.
A mono signal output through two or more speakers will still be mono, as the same content or audible information is being produced by each speaker.
monophonic - Having a single melodic line; monodic. Dictionary.com
