Not sure if this'll help. But this is a diffuse field graph of the K702's frequency response compared to some other well-extended headphones with a fairly neutral response. Might give you a little better idea where some adjustments in the K702's response could be needed.
The AKG K702 is the black curve. And all of the response curves are normalized to 1 kHz. So you'd probably want to leave that band pretty much alone. Or only make small adjustments to it. And do most of your adjustments with the other bands, where the response is more off. Since you only have 10 controls to work with though, you will probably have to make a few compromises in some spots.
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I would not try to raise the sub-bass as high as the Apple APM and AKG K371, because the bass may begin to distort. You could try raising it up at least a few dB though, so it's close to the Senn HE1, for example. And may also want to bring the level down a bit at 250 Hz, so it doesn't start to sound too muddy there.
You should also use a negative
preamp setting to prevent clipping in the lower frequencies where you've boosted the bass. If you raise the level at 32 Hz in the sub-bass by +5 dB, for example, then use a
preamp setting of about -5 dB to ensure that louder sounds aren't clipped in the sub-bass.
Some general settings or ranges you might try as a rough starting point based on the above graph...
32 Hz - Up at least a few dBs.
64 Hz - Up a couple or few dBs.
125 Hz - Ok as is, or maybe up a dB.
250 Hz - Down a couple dBs.
500 Hz - Down maybe a dB. (Or possibly less.)
1 kHz - Ok as is. Or maybe up a bit to help balance out the drop at 2k.
2 kHz - Down at least a few dBs.
4 kHz - Probably down a few dBs. You will have to play around with this though (and probably also the levels at 2k and 8k), to achieve the best sounding balance to your ears between the dip at ~3.3 kHz, and the peak at ~5.5k. The 2 kHz band should definitely be set somewhat lower than this 4k band though.
8 kHz - Down at least a couple dB.
16 kHz - Probably down a couple dBs. But it probably depends on how much air you want.
Link to Ora's graphing tool, if you want to try using some other headphones as a guide for the response of your K702....
https://headphonedatabase.com/oratory/headphones