seinheiser hd25 clamping force

I have the HD 25-1's, and as much as the clamp doesn't bother me, I don't think I could wear them all day (8+ hours non stop).  If your planned use includes normal breaks like going to the bathroom, answering the phone, ect. then I can use them all day.  I don't have any issues with the clamp force, but some people are less tolerant than I probably am.  Like any other closed isolating headphone with high clamp force, if you can audition them before hand or can return/exchange them hassle free you'll be better off.  

My trick with the HD25 in order to relieve its clamping pressure is to hold the headband and lightly bending the headband outwards for about 30 seconds prior to wearing them. The headband is made of very, very durable yet malleable plastic which is not going to snap from a simple stretch like that. Once it's stretched I find the HD25 quite comfortable to wear for 2+ hours.

The plastic warps back into its original clamping pressure once you leave it off for a while, so it should be done before each wearing session. 

It might stretch a little, but it still holds on pretty good after over 2 years of use.  I have to shake my head side to side pretty hard (Like saying No) to get the headphones to come off my ears.  As far as burn in, kind of hard to tell if the headphone changes or you just get used to the sound.  Not going to go down that path of discussion, but I don't feel like it really changed.

If you say they "clamp too much," maybe you should consider selling them or better aftermarket pads and headband? Just a though.

After 2 months mine are no longer uncomfortable. They have conformed to my head. Try setting them on a box over night.