Currently have the Fidelio X2 and quite like it, but was wondering how the HD650 would perform compared to it (I'm still within the return period of the X2)? Symphonic metal and power metal for me.
I'd say it's decent with metal, but not ideal. Electrostats sound so much better than everything else, at least to me.
Depends on the amp. I find Fidelios tend to sound better with more reasonably priced equipment. YMMV. However, the HD650 has that weird scalability factor. They sound way different with a $200 amp and a $1,000 TOTL amp. I feel they sound a bit muddy and veiled unless they are getting primo juice... To the point that I don't like them very much. Again, YMMV.
Although I would describe the HD 650 as somewhat warm, smooth, and veiled, it thankfully wasn't very muddy for me, even driven from a Schiit Fulla. I should hear it from a "primo" amp. hehe
Oh hey! I almost forgot. I may buy an original STAX SR-Lambda soon. That's the same one you have, I think. But I need to decide whether or not to go for the SR-407 instead.