I think if Bozo points his nose midway between two speakers (so at an angle of 0, 0.5, 1 or 1.5) it should be isolated to those two speakers. I don't think there is a way to get a single speaker with the MultichannelPan, but if you increase the radius to 2 (or at least increase it beyond 1 which is on the imaginary circle), and put his nose at angle 0.25, 0.75, 1.25 or 1.75, you might be able to get close to a single speaker.