Earl sometimes writes in a manner that looks tactless, but that's just his style. He might say he simply doesn't mince words.If an array is used above the frequency where driver spacing is greater than 1/4 wavelength, dense interference results. Jim Griffin would agree that sucks. So specificity is required in any discussion like this.
One thing is for sure, and that is a single driver measurement is not sufficient to develop a crossover for an array. Array geometry information is required.