How to do accurate half space measurements in sub-optimal environments?


The directivity and other basic acoustic basic data of transducers are typically measured under half-space condition emulated by large baffle setups in anechoic rooms. However, measurement irregularities may arise due to:

· Parasitic wave components from the acoustic shortcut and baffle edge diffractions

· Mechanical vibrations from large baffle which emit parasitic sound and also disturb the measurement results.

To overcome these common drawbacks we recommend trying the holographic measurement approach with KLIPPEL’s Direct Sound Separation module with the new SCN Near Field Add-On providing a virtual infinite baffle. The demo in our product video shows a directivity measurement of a small woofer mounted in a baffle. The transducer is operated in free air and measured in the front half-space.

By the way, measurements in a baffle are also available using the larger brother of the workbench, the NFS Carousel hardware.

See the full article here