StruttTools|1/3 to 1/1 Octave Absorption converts a row of 1/3 octave absorption coefficients or reverberation times to a 1/1 octave row, which is entered into the active row of the worksheet.
Strutt prompts the user to browse for a row of 1/3 octave data to convert to 1/1 octaves, and checks to see that the selected row is a 1/3 octave row. Strutt will convert the target row into 1/1 octaves and display it in the active row. If the active row is a 1/3 octave row, then Strutt will fill in the octave band centre frequencies of the 1/3 octave row with the values.
Strutt calculates the 1/1 octave coefficient as the arithmetic average of the 1/3 octave values.