Downloaded the Accudio by GoldenEars app for i-devices. They don't have settings for everything, and some of their settings are really questionable. The B&W P5 setting kills the bass and makes the P5 shrill - I don't get that at all. But it's a professional EQ app, as witness the perfect job it does with the DT770-32LE. So I tried the P5 setting for the M100, and being slightly bright I pulled the top slider down 2 notches and the 2nd slider one notch: Nirvana! If you'd like to hear some real bass detail with the M100 try this app and setting and West End Girls by Pet Shop Boys - yummy!
When I log in now, the header says "You are not allowed to post new content in the forum."
EDIT: And now it's back to normal. Computers, huh?