Hello,
1. Do these headphones have any differences from the reference DT 700 Pro except another label and black pads instead of gray?
2. I plan to use these headphones together with SoundBlasterX G6. Which impedance (80 or 250 Omhs) is better to choose for this particular sound card?
They have the same drivers. Just 2 difference: the branding in the cups dt770 pro XX ohm vs dt770 pro limited edition xx ohm. The other is the pads. Black pads are stiffer than the grey ones ( subtle comfort and initial sound, not significant. They became the same after they are worn out. You can buy replacement pads in any color if you want to change them from Beyerdynamic at anytime)
i haven’t used that amp. But the 80 and 250 have a different sound signature. 80 ohm more bass less treble. 250 ohm have more treble and some said is more cleaner and detailed. Some users also said they power requirements in both model is actually pretty close( if you want to take advantage of the extra bass), the 80 ohm requires more power for the bass.
I haven’t try any of this model but I will join the drop for the 80 ohm I want a closer back with bass.