Optimization of an Acoustic Waveguide for Professional Audio Applications

M. Cobianchi[1] and R. Magalotti[1]
[1] B&C Speakers S.p.a., Bagno a Ripoli, FI, Italia

In modern live sound reinforcement there is a growing use of line sources, obtained through the stacking of many loudspeakers with properly controlled wavefront shape. Thus the use of waveguides is mandatory in order to modify the shape and size of the wavefront exiting from professional compression drivers. With the help of COMSOL Multiphysics®, we have designed a waveguide featuring an integrated acoustic lens that achieves the required phase coherence in the output sound field. This paper compares the 2D and 3D simulations of two different prototypes with real measurements and with a third simulation without internal lens. A cost/benefit comparison is drawn between 2D and 3D results, and hypotheses are made about the discrepancies between simulation and measurements.