Bass Ratio

The bass ratio is the relation between the reverberation energy in the frequency range up to 125Hz and in the frequency range between 500Hz and 1000Hz.

bass ratio formula

bass ratio range 125Hz/250Hz + 500Hz/1000Hz

For music the bass ratio should be between 1,0 and 1,3 and for speech it should be between 0,9 amd 1,0.

See: Reverberation Time and Concert Hall Acoustics.