How are the 599 drivers angled? That's interesting. Does that affect specific head shapes?
The baffle it is mounted on is angled. Same construction as the HD560S.
Does that affect specific head shapes?
It does affect ear shapes more so than not angled headphones.
After reading this I tried moving the cans around my ears but it didn't seem to affect the sound much, definitely nowhere near as much as the difference between the EQ'd 599 and 660S. Holding my hands over the cans made a far bigger difference by making them more closed.
As can be expected. However you cannot de-angle the HD599 and angle the HD660S.
Holding your hands over the cups kind-of turns them in (semi) closed headphones. This makes the sound very different.
So I am just trying to make the 599 frequency response sound similar to the 660S, but with a little extra bass.
You can do that by damping the rear side of the HD599 driver which requires opening them up and applying the right amount of damping in strategic places.
Not easy to do and requires measurements.
Or you can apply some EQ.
And even then they won't sound the same as the drivers are quite different.
I find it strange that the Oratory EQ settings for both don't sound anywhere near the same.
I don't. Chances are (pad condition and product variances not withstanding) that with the applied EQ they might measure quite similar on Oratory's test fixture (with the averaging he does) but that does not mean they will 'measure' the same on your ears as your ears, with a high degree of certainty, do not comply to the standards used in his measurement fixture.
People assume an industry standard fixture and measurement protocol used will provide the absolute reality. In reality it is merely an indication valid for that particular test fixture ONLY and also to the applied (and basically not accurate) target where it is put up against.
Your ears and ears of others are not the same. Above several kHz your ears may differ many dB's.
Below 100Hz your situation (not applicable for your headphones) may also differ.
Between 100Hz and a few kHz the standard measurements should be fairly close to most ears. Tonality is mostly determined within that band but certainly also below 100Hz and above 5 or 6kHz which may very likely be the main reason why headphones are heard differently despite being somewhat closely matched (within a few dB) within that bandwidth.
The professional guys doing those measurements are all well aware of the limitation but the audience wants 'something they can use' and indeed it does bring the response closer together..... just not the same. That is not possible.
Measure the same headphone on various test fixtures (they can even conform to certain industry standards) and or with a variation of available pinna and or couplers, use different targets and or test protocols or even smoothing and you will come up with many different EQ's. One of them might be closest to your personal hearing than others but are most likely not fitting exactly...
The fortunate thing is that it really is not that important to be able to enjoy music.
Your hearing is highly adaptable and does not really care if it slightly 'off'.
This means most of these EQ's are 'good enough' and provide improvements in tonality.
It's just when you compare them AND have level matched the headphones before comparing (VERY important aspect when comparing headphones) you might still be able to detect differences.
In the vast majority of cases where someone 'compares' headphones the level differences (all headphones have a different sensitivity) are most likely causes by level differences.
I have no way to tell which is the culprit in your personal case (or which combination of effects)