  In this paper we continue to study the feasibility of active manipulation of
Helmholtz fields and by using an improved and more robust numerical strategy we
present a detailed sensitivity analysis for the method proposed in our previous
works. In this regard, we study the behavior of physically relevant parameters
(i.e. source power, control accuracy, stability) with respect to variations in:
the type of control regions (bounded or unbounded), relative position of the
control regions, distances between the control regions and the source,
frequency range and fields to be approximated. We produce strong numerical
evidence indicating the accuracy of our scheme and in the same time develop a
better understanding of several important challenges for its physical
implementation.
