[RockStar2005]

Does anyone know what the clamping pressure/contact pressure/clamping force of these 3 headphones is?! I just bought the Oppo PM-3 headphones which is listed as having a clamping pressure of 5N. But I can't find this info on the other 3 headphones. I'd like to know before my PM-3s come in (prob a week from now). The HD 598s were a bit too tight on me, so I returned them. The K550s and the 1As (my current headphones, and what I will be comparing the PM-3s to) however were/are not tight on my head at all! I'm hoping the PM-3s are closer to the K550s or 1As, but I won't know for another week. 
 
If anyone knows, please post! Even if you only know 1 of the 3. 
 
Thanks in advance!!!