For those wanting GRAS measurements:
This is @antdroid’s unit. Interesting to see the usual 2khz dip there. I initially thought the bass response here was showing minor air gap behavior with the gentle rise into the sub-bass, but it’s tough to tell because the resonance frequency is so freaking low that it doesn’t make much difference. You see this to a certain extent on both V1 and V2, but V1 was a bit more linear in a downward fashion with less change and a lower resonance frequency. I suspect in this case it has to do with the way the pads seal to the headphone (the clips), and less to do with coupling to the head.
Here it is with an actual air gap:
Notice how you do still see a dropoff, and this is more noticeable on this unit than on the V1 (V1 didn’t change at all).
And Free Air:
So this is where it actually shows a rise, contrast this with free air from HE6se V1 (purple is V1):
If this is confusing, essentially what’s going on here is that the headphone is deliberately being held a centimeter or two away from the rig to see how the driver behaves in free air and where the resonance frequency is. The limitation on this is that you can’t really control for exact distance all that well since that’s not what the rig is intended for, but so far my initial testing indicates that maybe there’s more going on with the V2 than just a tuning change. Pad material and connectivity to the headphone is another potential factor, so more testing needs to be done on this.
In any case, here’s the on-head response (teal is on-head) to check coupling integrity:
You can see that bass level agrees with coupling on the rig, indicating that the rise into the sub-bass likely isn’t actually due to any significant air gap behavior (unless it’s getting the same interaction when worn… possibly). At the very least, it’s likely controlled by a different factor because of the air gap and free air results shown above. It could be a mild form of it though, like the pad’s connection to the rest of the headphone as mentioned.
Overall… this is an absolute beast of a headphone and it’s making me kick myself for not jumping on that Adorama deal. Good lord does it ever slam. Soundstage and space isn’t the greatest but the detail on this is super impressive, as is the separation and control during busy passages.
Better techs than the V1? Yes I think so. V1 sounds more ‘closed-in’, and that’s after EQing both to the same target (roughly).