A new transaural system referred to as a ``stereo dipole'' reproduction system using a closely spaced pair of loudspeakers in front of a listener has been introduced recently. Computer simulations using theoretical models, in which the listener's head is assumed to be a perfectly rigid sphere, revealed that sound field equalization by the SD system including inverse filtering and also for the virtual source reproduction can be achieved in a wide range of area relative to the standard loudspeaker arrangements. This paper will deal with a further investigation of the SD system in terms of the controlled acoustic field around the head. The theoretical model used in the computer simulation is extended so that one can calculate an impulse response at any point while considering the influence of a rigid sphere. This model is used to compare the sound field around the spherical obstacle due to the SD system with one by the ordinary transaural system.