Quote: Very informative, thanks. So higher numbers are better? Is there a compromise made? A little more explanation would be nice, or some info on where to read.

The ohm is the SI unit of electrical resistance. I'm pretty sure lower is better, but anyway my pc350s hurt my ears at around 33% windows volume lol.

Quote: SRH840s have an impedance of 44 Ohms :)

By efficiency you mean impedance? 150 Ohms.

I just realized, would the details I'm looking for come out more if I got a proper amp? The problem is I don't really know where to get an amp retail and I can't really order anything right now.   I have an xfi card, not onboard.

Would hd201's really be an upgrade from pc350s? They're both closed sennheisers and the pc350s use the hd595 drivers...  

Thanks for all the replies. While positioning is very important to me, I feel like I love music just as much as I do gaming. I'm not only looking for positioning. To be completely honest, if you pay attention enough you can usually tell where something is even on terrible headphones simply...

I'm really looking for something I could buy retail, so if anything from http://www.long-mcquade.com/departments/43/ works well I'd prefer to go with that route.

I've heard some great things about the a700s as well but I don't know where I could find them retail. I hear the PC350s/PCX350s are similar to the HD555s but closed. Has anyone tried the SRH840s and HD555s or even better PC/PCX350s? If so I'd like to know how how they compare, and if it will be...

I'm going to get straight to the point instead of writing up a long paragraph.   I currently have PC350's. I am aware that these were a poor choice. I'm looking for closed headphones, isolation is important to me. Portability is not important. I listen to mostly metal. I play FPS games...