Here are the Susvara Unveiled measurements:
Raw (B&K 5128)
Calibrated (B&K 5128)
HpTF Variation (5128 & GRAS)
Here we’re comparing the calibrated results across two different heads. We can do this by using the rig-specific DFHRTF calibration for each system, and the outcome is a comparable dataset that shows HpTF variation across two different heads.
So in short, this shows how the headphone behavior changes from head to head. In purple is the response on the B&K 5128, while green shows the response on the GRAS ‘head’. You can see it measures a bit warmer on the GRAS head in a few spots.
Comparison with OG Susvara (B&K 5128)
I don’t think it’s as straightforward as one being outright better than the other. Some people who have difficulty with the OG Susvara’s upper treble will have an easier time with the Unveiled, but those who are more sensitive to mid/lower treble might find the Unveiled more fatiguing.
When I did my earlier measurements of the original Susvara I noted that relative to High Res Harman there is quite a bit of excess treble around 11khz that some may have found fatiguing. I never personally had this issue, but this is one area where the Unveiled is notably more subdued.
At the same time, the mids are definitely better on the Unveiled, being more filled in around 2khz. Not so much that the headphone sounds ‘intimate’, so it still has the spaciousness effect to it, but not as lean in that region as the original, sounding more cohesive overall.
Impedance curve
Note the rated sensitivity is still 86dB / mW so even though its low impedance it’s still recommended to use an amplifier.
Less Important Metrics 
Harmonic distortion
95dB
105dB
114dB
No issues with harmonic distortion. Even at extreme volumes it’s largely kept under 2%, and at normal volumes it’s completely gone.
Excess GD
No issues with ringing or internal resonances - this also indicates the headphone is sufficiently minimum phase and as such we don’t need to worry about any time domain information as in this case it’s proportional to FR.
Notes
- Easier to drive than the original Susvara but still needs an amp
- Build and comfort are a bit better than OG Susvara I find. I especially like that they ditched the silly wooden inlay on the original Susvara that always looked gaudy to me. The new one looks a lot better.
- The lack of a grille makes me extremely nervous, having worked with planar diaphragms in the past. Yes… the people buying this headphone probably won’t be using it with loose screws around that could get yeeted through the diaphragm, but there’s a lot of open surface area here that can very easily get punctured from any random object, even non-metallic things. People don’t realize just how fragile these diaphragms are, and I have to say that not having a grille or mesh of any kind is just categorically a bad idea.
- To combat this issue, which HiFiMAN are also well aware of, they’ve supplied magnetic covers to attach to the grille when the headphone is not in use… I would implore folks to remember to use these covers, but do not think this makes it a competent closed-back headphone. It does not.
- Subjectively it sounds every bit as detailed as the original Susvara, just with some subtle changes to the tonality as indicated above.
So in summary, they definitely improved on some things with the Unveiled, particularly the midrange. But it’s also not true to say the Unveiled is better in all regards. I do expect many will like the Unveiled more, but I have my concerns about the design itself, and having exposed drivers to the world the way they’ve done here should be met with a certain amount of criticism. Judge for yourself how much you think is appropriate.
When talking strictly sound quality, the the Susvara Unveiled is a worthy entry into the flagship arena. And even though it’s not better in all aspects, the changes are significant enough to where those who didn’t like the original Susvara have a reason to give the new one a listen.