It's entirely up to you of course, but I just think it's pointless when you have to have the volume at a mere 8% before it's too loud.
The headphones sounding better with when set to higher gain, is because gain boosts the volume. We automatically assume that louder = better sound quality.
If someone were blind tested with what they thought were two different headphones; but they were actually the same model of headphone, just one pair playing the same music but a bit louder than the other pair. You could pretty much guarantee that the majority of people would say that the pair of headphones playing the louder music are the better sounding.
Also; you may not do this, but I've seen people say that they have different programs/apps set at different volumes within the Windows volume mixer. The lower the master volume, makes it harder to set different apps at different volumes, as you only have a small amount of leeway. I've done that in the past, and trying to do that with master volume set so low, is a pain in the butt.
No reason why you shouldn't continue using high gain though, if that's what you prefer to do. Horses for courses and all that. Just trying to explain giving the headphones a higher gain setting, doesn't actually improve the sound, it just makes them louder for any given % of volume.
For low gain 80 and mid 150 I still had it at 8% but those settings seem to make the AKG K702 sound too coarse.
Even on the Creative Sound Blaster Audigy 2 ZS I have the Windows volume at 21% and the dial to 9 o'clock for the SMSL sAp Pro II AMP.
