kypfer

No, it won't work at a distance simply because there's no effective channel seperation at the point the microphone is located. All the sounds received at the dish will be received over the whole surface of the dish, so a "blade" down the middle of the dish will have no effect. You may have some success with two mono "rifle" mikes, individually aimed at the sound sources, assuming the sound sources are sufficiently far apart for the mikes to be able to differentiate them. It's all down to the effective angle of acceptance of the individual mikes and the angle between the two sources.