100 Things #62: Make Directional Measurements with Polar Plots in SoundCheck

SoundCheck’s Polar Plots make directional measurements simple. No matter what device you are testing, whether it be a VR headset, spatial audio, or headset sound leakage, SoundCheck can automate the measurement and turntable control. This means long high resolution measurements become as simple as starting a sequence! We even have a free, prewritten directional measurement test sequence using the new Portland Tool & Die MDT-4000 turntable, available here.

Make Directional Measurements with Polar Plots in SoundCheck

Try our loudspeaker polar plot measurement sequence for yourself!

Our polar plot sequence measuring a loudspeaker is pre-written and ready to use. This sequence measures the polar response of a loudspeaker in both the vertical and horizontal dimensions and displays the measurements on polar plots. This sequence is designed to work with the Portland Tool & Die MDT-4000 turntable.

Video Script:

Making directional measurements in SoundCheck is simple! SoundCheck supports turntables from a variety of manufacturers including Outline, Linear X, B&K and of course, Portland Tool and Die. These can all be controlled through a custom step in SoundCheck to be operated as part of an automated test sequence. Let’s take a look. 

Here I have a Portland Tool and Die MDT-4000 turntable – this a great turntable, by the way.  I’m going to use this to rotate a speaker, and I have a stationary measurement microphone to capture the recorded waveform. And of course I have SoundCheck on my laptop, along with an AmpConnect 621 Audio interface.

Here’s a  simple loudspeaker test sequence that plays a test signal through a loudspeaker and measures the response. Now let’s say I want to measure the response of the speaker every 10 degrees for a full 360 degree rotation. I just need to open up the test sequence….And I am going to add a custom step telling it to rotate the speaker by 10 degrees and re-measure, saving the results in the memory list and plotting them on a polar chart, now I’m going to loop that whole measurement procedure so we continue moving it and measuring until we do a full rotation. And now I’ll edit the display step to get the results output to a polar plot. Now let’s run the sequence…and there you are – fully automated directional measurements! 

There are many ways to use this functionality, for example directional measurements on smart devices with microphone and speaker arrays. You can also put headphones or VR headsets on a rotating head and torso simulator and measure the sound leakage that occurs when the noise inside the headphones leaks outside to the point where it’s audible to others around.  There are also many applications in spatial audio measurements. 

If you want a quick way of getting started with directional measurements, head on over to our website where you can download basic directional measurement sequences for speakers and microphones for a variety of different turntables.