Polar Plot (Outline ET250-3D Turntable) Loudspeaker Sequence

This sequence measures the polar response of a loudspeaker in both the vertical and horizontal planes. It is designed to work with the Outline ET250-3D turntable and contains all the necessary commands to automatically rotate the turntable’s platter when the SoundCheck host PC is connected to the turntable via an Ethernet/LAN connection. The sequence uses a log sweep stimulus with the Time Selective Response algorithm so that the measurements can be made in a non-anechoic environment. Note that the analysis step’s time window needs to be adapted to the user’s measurement space. The ET250-3D custom control step will also need to be configured prior to running this sequence. The sequence plays the stimulus and measures at 10 degree increments from 0 to 180 degrees. This process is repeated with the speaker positioned horizontally. The two results are mirrored to display full 360 degree polar plots for each axis. A directivity index curve is also calculated for each axis and is displayed at the end of the test.