Sander deWaal said:

Well if some have the audacity to think that all cd players and amps
sound the same why not also speakers?

Short answer : physics.

For the long answer see either one of Howard's books, note.

Ferstlerianism has a profound effect on what's known of physics. For
example, Ferstler preaches that mass can overcome inertia and that
causality does not exist.