Your dead on in your veiw of the cable changing right before your ears, My Ac-10 has 280hrs of play time but as soon as it hit 270 hrs something very spescial happened the sound stage became emence details that where buried deep where effortless and at 282 hrs its still giving up more unheard sound, I had thought the 300 hr breakin was to much , but its dead on, I may pick up a Ac-12 down the road but the Ac-10 once broken in is a hella good buy!