What conceptual departure characterized the Ambisonics system conceived in the 1970s?

It was not tied to a fixed number of speakers and adapted to any configuration.

The Ambisonics system, conceived by a British research institution during the 1970s, represented a significant conceptual shift in the methodology of spatial audio reproduction. Unlike previous multichannel formats, Ambisonics broke free from the dependency on a fixed speaker count or arrangement. This flexibility meant the encoded spatial information could theoretically be adapted and rendered appropriately for virtually any existing speaker configuration, moving decisively away from the restrictive 'one-channel, one-speaker' model that defined earlier systems. While initially slow to gain traction, this inherent scalability has rendered Ambisonics highly relevant for modern applications requiring adaptable 360-degree media playback.