I'm not surprised you hear a difference
@yabadaba . All I can say is that d10 uses ESS dac while d70 uses AKM chip. I have already conveyed my experiences using both dacs in the Topping nx4 dsd (ESS) and Fiio Q5s (AKM) and clearly I could hear differences. I use both equally now and I enjoy both. Having said that, I respect what most experts here are saying that DACs with equally well measured data will and should sound the same.
Yes, I'm someone who leans strongly towards science and this forum has been a fresh of breath air for me and has reigned in some of the rubbish that get's spouted elsewhere. I know there will be a scientific/measurable explanation for the differences we are hearing, but possibly that is not captured by (or discerned from) the tests being covered here.
I'm not skilled/experienced enough in this area of science to confidently propose reasons and so happy to be told this can't be the case, but in respect to frequency response I wonder whether, (in this example), the sound difference might be to do with the transition between those frequencies, rather than their relative volumes? I've been trying to avoid subjective description of what I hear (because I agree that a lot of the terms are ambiguous), but I'll risk it briefly. The track I'm playing has a bass guitar prominent in the mix and each note sounds more defined with the D10, whereas with the D70 I don't hear (and feel if played loud enough) as much impact when the note is played, though the bass is still very much present.
So, I'm thinking maybe it's the initial change in the overall frequency response (when a bass note is played) that is being reproduced differently. So, it might be that a constant tone played at that frequency wouldn't capture that difference? Music I've played where the mix is more dense (and different frequencies are mixed up together more) doesn't reveal the difference I am hearing as much and with this type of music the overall tonal balance sounds very similar. I'm really just guessing/hypothesizing here and maybe this transition thing is already accounted for in one of the tests.