Peidpiper makes a good point. There are many types of EQ and each is best suited to particular applications. Manley's Massive Passive is a parametric EQ which could be used for room correction (2channel only) with the support of external measurement/filter calculation programs like REW. OTOH, it is best suited for (and designed for) equalizing the sound source for mastering. Contrast this with modern digital EQs (yes, I know the title of the thread) which can offer a very large number of filters with complex parameters more suitable for the complexity of room acoustics. The first step is to determined what you are trying to accomplish in your particular room.
Kal
Kal