It may indeed be distortion, if that's how you'd define it.

I was expecting some fuzzy sound, some choppy-ness, some Stratocaster-in-a-Fender-Twin kinda sound. THAT kinda distortion.

I never heard it before because the speakers, too, are brand new.

Now, my OLD speakers - THEY have distortion. I may have to bump my standards up a notch or three to become an appropriately critical listener.