To be fair I have boosted the bass in all my headphones to some extent, and I can understand that not being to some people's taste if they prefer dead flat sound. For those who like an extra oomph to their presentation they seem to love the ZMF's.
I don't know if I've ever explained why I tune this way publicly, but the reason is that when I used to play more music, acoustic guitar and banjo (still do as much as I can). And I wanted my headphones to sound the same way as it would to stand by a bunch of people playing instruments. As I got more into making headphones I found that some coined this "stage monitor" tuning. I can see why, as I think to those who have been around a lot of live instruments, it just seems more "realistic" to have that oomph in the low bass, because that's what it sounds and feels like to be around real instruments in close proximity. It allows you an easier ability to "feel the wood" of an acoustic instrument rattle a little bit, and tuning the bass up below 125hz a little bit is the best I can do with headphones to re-enact this.
That being said, I totally understand that everyone has different tastes, and if needed I'll do my best to accommodate with a custom tuning!
Just reading this for the 1st time, 13 months after the fact--and it's amazing. Much is explained here about the "tuning" of audio gear.
I've been active in high end audio for many years (recently focusing on desktop audio & headphones). And I've been consistently (unhappily) surprised by how unnaturally bright & edgy much well reviewed audio equipment is. My objection is simple: besides the fact that "clinical/accurate" tuning hurts my ears, it doesn't sound anything like what I hear from live instruments in concert halls or big jazz band. There, the bass & lower midrange feel totally different than the upper midrange and treble. The low notes--especially from massed instruments like a cello section--hit you in the midsection. They light up your diaphragm & almost move your lungs a little...sounds that are felt AND heard. The treble, on the other hand, usually sounds "brilliant," shimmery, like it's dancing around your head--but w/little physical impact.
My first really big-time audio system had multiple tube amps, bi-amping, and 2 X 12" subs in each speaker column (Vandersteen 4's). The crossovers were 6 dB/octave, the gentlest slope possible (to preserve musical phase). Those shallow crossovers limit absolute dynamics & volume a bit, but they also reduce the "edgy," razor-sharp quality of many transients. That system made music sound & feel pretty close to the real thing. I relaxed and just heard music (vs "listening to equipment").
Now, with headphones, it's more challenging; they can't surround my body with impactful vibrations. So the tuning becomes ultra-important; the bass will ideally be a bit above flat, yet rich in quality/nuance while not bleeding into the midrange; and the treble will, if anything, be slightly below flat at the top (because high notes decay so quickly IRL). That's a difficult balancing act. I've only heard 1-2 headphones do it, but they're nowhere near the ambitious quality & design of the Omni/Ori.
I have an Ori on order...can't wait to hear them. And appreciate this "tuning" comment...in a very indirect, non-confrontational way, it makes the case for more "reality" in the sound of audio equipment.