A room’s lowest modal frequency is its first axial mode along the longest dimension

Evidence

Using Equation 6.21, calculate the modes as follows. The lowest frequency mode is the first axial mode along the longest dimension of the room, which is the (0 1 0) or axial mode in this example, so the lowest modal frequency in the room is: The mode with one half wavelength along the 3. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1986

Categorization

• DEFINE: Introduces the axial-mode labeling and the rule that the longest dimension sets the lowest mode.
• XREF: Pairs with the earlier chapter material on room modes and standing waves in enclosures.