This filter specialized in changing the overall sonic character of a track in fine nuances. It features two controllers per channel and is capable of flexibly producing convincing results in no time at all. Whenever a classic shelving filter would be too limited and a fully parametric filter would too much, the Niveau Filter is the efficient and elegant solution.
Its main task is changing the proportions between high and low frequencies. It works like a pair of scales: Dependent on the gain setting around a selectable center frequency, the high frequencies are boosted up to +3 dB while the low frequencies are simultaneously attenuated by -5 dB maximum. Turning the gain controller into the other direction will cut the treble and boost the bass instead.
The filter type used for this application is an all pass variant with a flat frequency response that changes its phase according to the setting of the frequency controller. If the signal that went through the all pass is mixed to the original signal, everything in phase will be boosted while out-of-phase signals will be reduced.
Because the filtered signal is mixed to the original, the genuine structure and impulse-response remains almost completely intact. None of the amplifiers is shortened in its frequency response, resulting in an open and dynamic sound. Boosting and cutting the selected frequency-areas at the same time makes it much easier to influence the character of a track ('bright' vs. 'dark') than with standard equalizers.