Hi Chris,
Welcome and I'd only add to the comments here that the ultra-controlled scientific listening tests I did of various lossy algorithms at the NRC in Ottawa (along with other so-called "golden ears" from Canada and the US) essentially concluded that if you use 320 kbps data rates, it is "largely transparent" for virtually all music except a few eccentric instruments (castinets, harpsichord).
So you should be fine with the M60s. David is correct--once you have a lossy file, you cannot regain the data that's discarded when it's been processed by an MP3 algorithm or similar (unless you own the original unprocessed source).
And if you do drive across Algoniquin Park to Axiom, watch out for the moose and the deer wandering on to the highway.
Regards,
