What is filter type "Modal?"

[Richard May]

I've looked for a good explanation -- can't find one.

ON Modal Fc 100 Hz Gain 3.0 dB Q 5.41 T60 target 100 ms

What are these parameters and how does one leverage them?

[Etienne Dechamps]

Equalizer APO uses the REW export syntax. The REW help page describes these as:

A 'Modal' filter type may also be offered, which is a peaking filter whose bandwidth or Q is adjusted by REW to match a Target T60 decay time. It is used to accurately counter a modal resonance whose decay time is known.

I think this is just an EQ design thing and they are most likely ignored by Equalizer APO, which only cares about frequency, gain and Q, as described in the Equalizer APO docs. In other words the extra Modal and T60 target 100 ms are just "comments" as far as Equalizer APO is concerned.