# Frequency Response Matrix

For an N degree of freedom system, it is an N x N symmetrical matrix whose elements are the frequency response functions between the various points on the structure.

Rows correspond to response points and columns to excitation points. For example, H46 is the frequency response with excitation at point 6 and response at point 4. The matrix is redundant, that is, by knowing any row or column, the other elements of the matrix can be computed.

**See also: **Frequency Response Function, Modal Analysis.

**Subjects: ** Noise & Vibration