this is a wonderful headphone; i run it on a resonessence concero hp and the detail it resolves is unbelievable.
for some context, i really love bass and treble; i find the hd800 needs a treble boost and the bass falloff requires that i absolutely crank the bass on them; i add 6.5db to the bass below 80hz on the hd800.
the dharma needs only a little bass enhancement; so i only add 2db below 100hz.
i also gain up the treble above 2khz - i start at midrange and amplify all the way up, effectively just attenuating the lower-mids.
 
to address the pain point other reviewers have been faulting them for, these headphones have a resonant frequency range around 9khz.
it has to be filtered out or the trebles get very, very shrill. it's pretty easy to do, i just put a peaking filter with a q2.5 falloff around 9khz with a -2.7db attenuation.
realize that, since it is a resonant frequency, if you elevate the volume going into the headphones, you have to increase the attenuation - the drivers will pick up the resonant range and amplify it unless you keep it waaaay down.
they're hardly the first high-end cans with a resonant frequency - the hd800s have one at 6khz that has to be filtered out as well.
 
i have some fit problems with the headphones; these are the first cans by enigma acoustics, so they didn't design them well for the large variety of head shapes that exist. the distance between the top of my head and my ears is small, so i had to modify them to stay in place. my friends with a larger ear-to-crown distance don't seem to have this problem.
they are also a bit heavy, but my baseline is the hd800, which is a very light high-end can.
 
while the bass response is very nice on these headphones, the treble is really the highlight. they are so responsive, when i compare them to my hd800s, i feel like i'm listening to my music through a wet blanket. i can't bring them anywhere near my sennheisers; i have to keep them in another room or i just can't listen to the senns anymore, which sound wonderful, they are just not anywhere near as revealing as the electrostatic tweeters in the dharma.
 
a note about my equalization workflow:
i use equalizer apo 1.1.1 for windows. it's free but you have to use windows shared mode for your output (it's a kernel audio enhancement filter) so i change my output format to 24bit so that there's no detail loss when i preamp the input to the equalizer to avoid clipping.
 
here's the contents of the equalizer apo text file:
Preamp: -2 dB
Filter: ON LSC 18 dB Fc 100 Hz Gain 2 dB
Filter: ON PK Fc 9000 Hz Gain -2.7 dB Q 2.5
Filter: ON HSC 18 dB Fc 2000 Hz Gain 2 dB
 
and a png of the curves:
https://i.imgur.com/N80BB4I.png

i've had this dac for a while and it was a major upgrade from the internal dac on my laptop.
 
the imaging is much better, the bass is much more well defined, the trebles don't tear, and the mids don't cloud out the entire rest of the dynamic range.
 
while there is hiss on my sr-535 iems, it isn't intolerable - it is mostly only audible when the source volume dips particularly low.
 
at the lowest volume setting (zero) the audio is barely a whisper in the 535's, but kick it up one step and it is much, much louder. there isn't really any in-between and sometimes, for background listening, i would really like an in-between. beyond about 5 it's just painful.
 
the other major problem with the module is the design. it sticks straight out of the usb port and having a headphone cable attached at the end of a stick causes a lot of flex that could potentially damage the port. so i had to buy a usb right-angle adapter for the device and make a metal support bracket to keep it from torquing apart my usb port in it's new orientation parallel to my laptop's chassis.
 
it's nice to have the usb-otg support for android. i've used it on my phone and it sounds great but the form factor makes it a little ridiculous. it always elicits comments, "why do you need ANOTHER headphone jack on your phone?" the response to which is, of course, just because it looks the same doesn't mean it SOUNDS the same. but that doesn't make it look any less hilarious to have a giant usb stick protruding from the bottom of a phone.
 
it would be nice if the device could handle 16 bit audio natively. seems like a bit of an oversight to handle several different sampling rates but decide not to implement something as simple as bit depth scaling in hardware. i'm seriously not intending to make so many puns in this review.
 
even with all these gripes, i'm not dissatisfied with my purchase. it's tiny, portable, compatible with most of my devices, and it sounds great, especially for the price point.