Zero Latency setting ensures that no latency will be added to your processing, making it even more applicable for live tracking. With decreased latency comes increased CPU usage and altered phase response of the outgoing audio.
Linear phase setting guarantees linearity of the filter phase, thus delivering ultimately clear and accurate sound at a cost of approx. 60ms latency.
Most of the time, this is the best setting to use when adjusting the overall spectral balance of your music. It is important to be aware that depending on the specific filter profile, this setting could introduce some pre-ringing to bass frequencies.
While this is hardly audible when listening to the overall spectral balance of a song, you should be aware of this possibility when working on solo drum tracks.
Min filter phase (Reference 3) setting ensures minimum latency of the plugin(approx 1.1ms) thus making it accessible for live tracking applications.
To ensure the minimum possible latency, this setting increases the CPU load of the plug-in.
As a natural property of minimum phase filters, this filter setting slightly changes the phase response of the signal which you can see when selecting the "Filter phase" curve under the "add" curves selector.
Optimum (Reference 4.0) setting brings together Minimum and Linear phase settings delivering clear and accurate sound at an affordable 20ms latency.