ADOPTING DIRECT FIELD ACOUSTIC NOISE TESTING TECHNOLOGY FOR THE REPLICATION OF DIRECTIONAL ACOUSTIC FIELDS: CHALLENGES AND RESULTS

Acoustic testing is a milestone of any space program.
Together with vibration and shock, the acoustic test is a
part of the mechanical test campaign. Traditionally, these
tests are carried out in reverberant chambers. In recent
years Direct Field Acoustic Noise (DFAN) testing is
gaining technological momentum mainly due to the
flexibility of the speaker system combined with state-ofthe-art centralized Multi-Input Multi-Output (MIMO)
Control algorithms. Multiple studies have shown that this
technology is fully capable to produce a sound field
which approximates the one generated by a reverberant
chamber and is uniform and diffuse. The goal of this
work is to explore, via test and simulations, a new
possibility enabled by a DFAN system: adopting MIMO
Control to produce non-uniform and directional acoustic
field. This paper reports the challenges and the
preliminary results obtained during a test campaign
where a medium-size DFAN system has been used to
replicate a diffuse acoustic field and a directional
acoustic field.