Listen to a great FM tuner and you will see. Cut off at 15000, by design for other doodads doing stuff up there. Not only are harmonics lost, but so is directionality from frequencies we do not even hear, but that our brains sense and interpret.
Correct, my plasma tweeters which are spec’ed to 100khz, I can bring them in even higher at 15khz and still sense/hear them doing good things for the harmonics, air and transparency even though my ESL are said to good to 20khz
Cheers George