I'm not sure what you mean by "matched by manual inspection" but I don't see how you can accurately match two drivers without using equipment to measure them. Those drivers would hardly be matched at all so I stand by my last post-- it would be obvious both in listening tests and in measurements that the drivers were not matched.
AFAIK every legitimate headphone company (i.e. all the big names that are popular here on head-fi) match drivers in all but maybe their cheapest models. That's why when you send in your headphones for service because of a bad driver they replace both. Beyer does that even with their $199 COP so I highly doubt that they would have unmatched drivers in their higher end models.
Edited by devhen - 3/28/13 at 7:37pm