This isn’t true unfortunately,
I could spend hours typing, and never communicate well this topic, but fortunately, someone already went to all the trouble, and even has nice pictures: http://korfaudio.com/blog36
I can attest to what they surmise that the Ortofon test record does work (3rd blog post). I find the high frequency sweep is more sensitive, hence more accurate, but it is an easier test for me than it may be for others. A single tone THD may be easier for most.
my point is that azimuth is best used to manage crosstalk, not channel balance. If I were faced with channel imbalance, there are other ways to correct it.
I could spend hours typing, and never communicate well this topic, but fortunately, someone already went to all the trouble, and even has nice pictures: http://korfaudio.com/blog36
I can attest to what they surmise that the Ortofon test record does work (3rd blog post). I find the high frequency sweep is more sensitive, hence more accurate, but it is an easier test for me than it may be for others. A single tone THD may be easier for most.