Yup. I like to use active xovers often as filters. A 3-way active will allow a bass sub crossover and also some kind of a step filter (well if you can call 24 db per octave a step). Anotch will of course require either a parametric EQ or a 4 way active xover (assuming you want to use a sub). f you don;t want to use a sub, of course, a 3 way actve xover should provide a satisfactory active notch. -akhilesh