Samples I've heard:
- HeadRoom: Absolutely horrible. Will destroy your hearing.
- RD #1: Only heard the modded version, which was still horrible. I assume when unmodded - as horrible as the HeadRoom K550.
- RD #2: Slightly better than the above, but still horrible.
- CT: Pretty good.
Yes, it's very weird. Looks like the same problem that the Beyer DT1350 seems to have. ie: quality control. Or else, it has been quietly 'developing' as a headphone. (I doubt that though since once they're designed, the companies tend to leave well alone unless there's a real problem)
Mine is one of the first out in the UK. Tomorrow, I'll have a new one so I'll compare the two.
I have my amp set at 100 ohms out and that seems to calm the sting in the top. (It's a valve amp as well) It still has its lively top end, but not as 'stabbing'. No bloom on mens' voices and yet it shows some really very deep bass on some recordings too. (So no hump in the mid bass to colour mens' voices)
I guess the K550 is on its way out since it's now being sold quite cheap over here in the UK but if they are so variable, you're not guaranteed a good one.
Mine doesn't seem bad in spite of being one of the first over here.
I tend to have to wear it quite 'high slung' in order to ensure a good seal as well. Higher than my other headphones anyway - so that the bottom of my earlobes are just touching the inside of the pads - I find I get a robust bass in that position.
I wonder whether the CT one is a more recently made headphone?