Here is a nice collection of headphone data sheets detailing frequency response and isolation measurements. Inner|fidelity has done a lot of work putting this together.
http://www.innerfidelity.com/headphone-data-sheet-downloads
Brad
Hi Brad,
thanks for your link, it must have taken years to put that together.
One thing is sure, looking at some well know brands,
you cannot make a decision only according to the graphs,
because some of them look terrible,
so it's better to listen and maybe then look at the graphs.
Thanks again, very informative.
Guy 13 on planet Vietnam.
(I own a pair of Sennheiser HD650
driven by a Bottlehead Crack)