Ok. Understandable. I would suggest trying it at least. It is very unlikely that your ears will get you where you need to be. Imo, you’re correct to question it’s reliability, and the phones mic will definitely be less sensitive when you get down into the deeper bass frequencies. Still, imo it will be better, and at the very least , will be more consistent than ears. As far as setup, there shouldn’t be much. Set to to “C” weighting, and slow response. Make sure to keep it around ear level at the LP(listening position).