Failing to differentiate between a Martin and a Gibson, for example, each sounding like an acoustic guitar but missing the subtleties and nuances inherent with either, thereby diminishing the listening experience and nullifying the musician's investment. Before we can go on to the next step of making your system disappear, it must already be at the point where it has enough fidelity to make those subtle differences known. The disappearing act will not happen unless your entire system tracks true, from the mics to the loudspeakers. That is why I design and build some of my own com pon ents. It is uncanny in it's simplicity and even more profound in the way it works.
Localization is more dependant on time than on amplitude.
In other words, the sound appears to come from the source which is heard first. Popular sound systems place the main loudspeakers ahead of the musicians on stage in order to help eliminate feedback. In this configuration, the sound from the main loudspeakers reaches the listener first. Any sound from the stage will be heard a fraction later and assimilated to the loudspeakers, sometimes making them sound muddier. Assuming everything else is being done properly, merely delaying the main signal so that the PA sound arrives at least 2ms after the sound from the stage will shift the perceived sound source from the loudspeakers to the stage.