  We report the experimental studies on an acoustic scatterer consisting of a
pair of coupled decorated membrane resonators (DMRs) that exhibits near extreme
contrast in reflection asymmetry and strong Willis coupling coefficient with
amplitude of 2.5 and polarizability cross term of 1.1 x 10-8 ms2. The design is
based on the theoretical analysis using the Greens function formulism we
developed earlier. The clean line shapes of the real and the imaginary parts of
the Willis coefficient clear show, even by visual inspection, that the
Kramers-Kronig relations are satisfied. Theoretical analysis agrees well with
the major features of the experimental results.
