I had _the exact_ same issue in both speakers when they were delivered, and it was the crossovers loose from their moorings. Aparently, some of the 3M materials they were using was not holding the crossover in place.
I'd recommend contacting Talon for advice, but it appears youve tried that already. Not sure what to tell you from here, but 95%, your problem was the same as mine. They sent me a replacement new pair, but that was four years ago.
I no longer own them.