Have you tried swapping the wires at receiver terminals just to make sure it’s the QS8 and not something else in the chain? Next thing you might want to do is play something that rumbles and listen to see if you can localize where it’s coming from on/in the speaker. Also I’d email Axiom since if anyone has heard of a problem with their speakers it’s them.

3M80 2M22 6QS8 2M2 1EP500 Sony BDP-S590 Panny-7000 Onkyo-3007 Carada-134 Xbox Buttkicker AS-EQ1