Pulse-to-Carrier Modal Filtering in the Great Pyramid Interior: A Coupled Acoustic-Network Model from Published Geometry

This working paper evaluates whether published dimensions of the Great Pyramid's internal architecture support a coherent source-to-load acoustic-network model. The novelty is not the existence of chamber resonances, but a proposed impulse-to-modal-carrier transfer model in which published interior dimensions form a coupled acoustic network. The analysis does not claim builder intent, final purpose, or a preserved source mechanism. The proposed model begins with a conditional broadband pulse-like input at or near the lower Queen's Chamber niche or adjacent niche-cavity region, treated as a source-side pressure-cavity boundary. From there, the interior is modelled as a coupled chain: Queen's Chamber modal coupling, horizontal-passage feed, Grand Gallery phase/delay behaviour, antechamber stateful coupling, and King's Chamber / granite-stack load concentration. The principal observation is that this chain organizes around two adjacent low-frequency carrier families. A lower family near 29.3 Hz includes the King's Chamber vertical mode, the Descending Passage 18th harmonic, and the Ascending Passage 11th quarter-wave under reconstructed boundary conditions. An upper family around 32.7-33.1 Hz includes the Queen's Chamber and King's Chamber north-south axial modes. A fitted Grand Gallery effective phase length defines a one-parameter harmonic comb with fundamental f0 approximately 3.6775 Hz; its 8th and 9th harmonics fall near these two families. A separate Petrie-reported Grand Gallery slot-zone datum provides a related lower frequency length scale but is kept analytically distinct from the fitted comb. Under this interpretation, the King's Chamber is not treated as a newly discovered resonant chamber or a single-frequency endpoint, but as the principal load region in a broader pulse-to-carrier acoustic network. The Descending Passage / Well Shaft / lower terminal is treated as a return/load and phase-conditioning branch. The result is not empirical establishment of purpose or operation, but a testable acoustic and structural-acoustic modelling hypothesis. This is the first public working-paper release intended to establish a citable record of the modelling hypothesis. Later versions may add source-apparatus refinements, numerical-ledger updates, and computational modelling results.