Re: Stair Cardioid Subwoofer Array
1. When speaker enclosures or obstructions of any type are in the sound path between the rear point of origin and the listening position, they will have an effect on the sound. When an obstructing speaker enclosure is powered (or shorted) it will have similar effect on the sound regardless of it's design, if left passive, the effects are dependent on the impedance curve of the particular enclosure. In an actual array, the only reason a cabinet would be left passive would be due to blown transducers or improper termination.
2. The effects are peaks and dips in the response as can be observed in Sebastian's "obstruction" tests with an non shorted cabinet, and my tests with a single cabinet, then with a flanking cabinet shorted and not shorted.
3. There are measurably different effects that result from arrays using different enclosure types, the resultant behavior needs to be equalized both for the array, enclosures, and room. Langston Holland's tests using EAW horn loaded enclosures in a "stair" configuration nearly a decade ago showed good results, but certainly would require different EQ and delay settings than a bass reflex enclosure. Every different array requires different settings, and will have differing polar response, even if the different arrays measure the same in one on axis position.
