A particularly useful waveform for modulation of the carrier (primary) beam of a parametric acoustic source is one in which the “self demodulation” which occurs for θ = 0 is vastly different from the θ ≠ 0 case. The particular modulation considered here has the property of transmitting a cw signal with a directivity pattern which peaks off‐axis while the on‐axis transmission consists of impulsive noise. For active sonar applications, this technique allows one to form a conical rather than endfire beam by filtering on‐axis energy from the echo returns. The MRA of the cw beam can be steered by varying the modulation or primary source level, thus allowing the possibility of higher volume scanning rates without sacrifice of angular resolution.