Sorry, Mark7, but for the life of me I can't place that picture. Is it one of the incarnations of the good Doctor? If so, forgive my ignorance. I'm mostly familiar with Tom Baker.
Look at the Beyer website www.beyerdynamic.com and look for the graphic of the 201's freq. response.
It's an almost flat line from 40hz to 18khz, now look to the graph of the SM57.
The 201 is an outstanding mic, I have three 201's that are twenty years old and still shine on many applications.