I'm wondering if there might be some kind of interaction with the drivers and amplifiers? They've gotta be pretty wide-range drivers, and I wouldn't be surpris

I'm wondering if there might be some kind of interaction with the drivers and amplifiers? They've gotta be pretty wide-range drivers, and I wouldn't be surprised if there's class D amplifiers in there. That can produce loads of power, efficiently, but high-frequency switching noise could be a concern. Might be worth measuring these with a reference microphone, capturing at something like 192k. Might only need 96k. You want to find out if it is producing 'ultrasonic' noise, particularly at high amplitudes.