Bass EQ that I mentioned fits into that Personal EQ you mentioned, as you might have more bass leakage with your headphone due to anatomy/fit and also just for preference. Some EQ's I've done for my headphones in the past I've also EQ'd broad specific areas after listening to various reference tracks of mine, for instance a broad peak filter around 7kHz for one of my headphones and also a similar one at around 1.5kHz to reduce shoutiness, but it's harder to use those specific broad filters as it's very subjective when you're getting that specific. In reality, I've found it's far easier to tune bass level to balance in with the rest, and the 105Hz Q0.71 Low Shelf that Oratory uses is very useful in that regard as it targets the bass without introducing muddiness. Another really good way I've found is to also tweak overall tonality using a Linear Tone Control through the whole frequency range (think a seesaw straight line motion hinged at 1kHz) - you can hit an almost perfect linear tone control by using the 3 following parametric High Shelf Filters with Q0.5: 63Hz/632Hz/6324Hz, you set the same dB level for each of those (positive or negative depending on if you want to brighten or darken the headphone respectively), only 0.1 or 0.2dB increments required on those to notice changes in the tonality.