The ear is less sensitive to low frequencies when listening at low volume. This plug-in is based on the Stevens-Davis equal loudness contours and allows the bass level to be adjusted to simulate or correct for this effect.

Example uses:

If a mix was made with a very low or very high monitoring level, the amount of bass can sound wrong at a normal monitoring level. Use Loudness to adjust the bass content.
Check how a mix would sound at a much louder level by decreasing Loudness. (although the non-linear behaviour of the ear at very high levels is not simulated by this plug-in).

Fade out without the sound becoming “tinny” by activating Link and using Loudness to adjust the level without affecting the tonal balance.

Credit: Paul Kellett