Noisebud has released an effect plug-in for measuring low end.

Evouyn measure the energy in the whole spectrum in both short term and an average about 20 seconds and calculate the percentage of the energy below 50Hz.
So why doesn’t it show a percentage? The first beta versions gave you a percentage in real time but we realized that the number wasn’t much use and rarely matched the number for the whole track.

We abandoned the percentage and tried to find a better way of illustrating the tracks spectral relation, we got the best result with the short term bar and the average displayed just as colors. This might change in the future.

Evouyn version 1.0 is free, while version 1.6 is donationware.

More information: Noisebud