On the Influence of Transfer Function Noise on Low Frequency Pressure Matching for Sound Zones

Controlling the sound field in a room with loudspeakers, requires information about how each loudspeaker radiates sound to the regions of interest. This information can be estimated by in-situ measurements of the transfer functions. However, noise in the estimates can severely deteriorate how well the sound field is controlled. Accurate transfer functions are especially important for sound zones, which rely on destructive interference between multiple loudspeakers. In the presented study, transfer function measurements from eight 10” woofers were repeated 30 times in a room. Pressure matching was used to create sound zones between 20-300 Hz. The performance is evaluated for individual and averaged transfer function measurements. Additionally, the effect of Tikhonov regularization based on the estimated noise in the transfer functions is examined.