Dunu Zen Pro - Official Thread

I can talk about this now. The DUNU Zen was released roughly six months ago. It was a project that I had excitedly been following for months; the graph looked good, and there was the undeniable allure of a single DD, endgame IEM. Alas, when I got around to hearing my review unit, I was…disappointed. The Zen sounded dark, congested, and generally harsh. I hesitated to drop my review, even prolonging it for months before eventually releasing it.

It’s worth noting that there were people who loved the Zen. But DUNU, highly receptive of feedback as they are, have since opted to release a direct replacement to the Zen called the Zen Pro. It will be released in due time with the IEM hitting international markets first. For now, myself and a number of other reviewers - MRS, Resolve, and Antdroid - were asked if we’d like to participate in testing of the IEM with an experimental twist. We would do blind listening without knowledge of the graph or running sine sweeps, write down our thoughts, check the graphs, and then re-evaluate. The Zen Pro was an ideal candidate for this because it was a brand-new IEM that no one had seen before; therefore, there were no existing impressions to confound our own. It was definitely an exciting prospect, as the opportunities for this stuff are limited.

Almost everything is exactly the same as the Zen physically. The only difference is a new titanium finish which I think looks even better than the original.

Zen Pro Notes (without knowledge of the graph, and with a couple hours of listening):

Generally, the overall tonal balance of the Zen Pro hits closer to neutral, whereas the Zen follows more of a dark V-shape (that, honestly, I find somewhat all over the place).

  • Bass notes are slightly cleaner on the Zen Pro due to less mid-bass. Clearly not as warm as the Zen on Dreamcatcher’s “Can’t Get You Out of My Mind”.
  • Pinna compensation has been dialed back slightly for a cleaner midrange. The perception of a cleaner midrange might also be because some of the bulk in the lower-midrange seems to have been cut. Zen has more texture and body with male vocals on Joe Nichols’ “Sunny and 75”. The Zen Pro’s transition between upper-midrange and lower treble, so say 3-5kHz, appears to follow more of a gentle slope than the Zen did. The opening of Loona’s “Eclipse” has less of a jut to the “s” consonances on the word “sparks”. It’s still not as smooth in this transition as, say, the Moondrop Variations though, as a slightly “glassy” quality pervades which probably isn’t aided by the quicker decay.
  • The Zen Pro is not as dark after 10kHz, but is still not particularly airy. Cymbals on Sawano’s “Cage” still lack extension, and the shakers are missing shimmer. The main difference would be that the 9kHz peak on the Zen has been attenuated for a smoother treble response. Percussive hits in the front-left channel of “Into the New World” sound more tonally correct (as does everything else about the treble in general).

The Zen Pro sounds less downwards-compressed than the Zen; however, most of the Zen’s issues in that regard stemmed from the treble response. I wouldn’t say the Zen Pro’s staging sounds like a particular improvement. It’s more so the layering department - distinction between individual instrument lines, vocals, and positioning - that has seen a considerable jump thanks to the tuning. I would say that timbre still has that slightly weird metallic tinge to it at times, perhaps due to a quicker decay like what the JVC FDX1 exhibits. The Zen Pro is still not as timbrally pleasing as the Moondrop KXXS, even if it does have better resolution.

Post-Knowledge of the Graph Thoughts:

Overall, I’d say my thoughts line up with the graph pretty darn closely. I nailed the pinna compensation and the 3-5kHz region, and mostly got the lower-midrange and bass regions correct relative to how the measurements depict the differences.

The treble, however, isn’t as smooth as I initially thought. Running a sine sweep, the peak at 8kHz is still fairly present - just the amplitude has been lowered relative to the Zen. So I was sort of correct about that. But there’s also an additional peak at 11kHz. I’m guessing it’s harder to notice the 11kHz peak on cursory listening because it’s been positioned higher up, near the air frequencies. This also likely contributes to the Zen Pro’s slightly metallic timbre, not unlike the Focal Clear (although not to that same degree). I do find myself noticing this now after having seen the graph.

Further listening does seem to indicate that the Zen Pro’s ability to articulate the “weight” and intensity of dynamic swings is weaker than the original Zen’s, It’s also flatter for range as whole; however, this is a small price to pay for the improved tonal balance in my opinion.

Final Thoughts

I like the Zen Pro. I hear a lot more of the Luna’s excellent technical performance and, even better, the Zen Pro is considerably more balanced in terms of tonality. To my ears, it presents a decided improvement over the Zen. You might be surprised to know that isn’t something I find with many “Pro” and “MK.II” versions of IEMs.

Now, whether it’s competitive for the projected asking price (still TBD, I believe) is more difficult to say. Within the context of single-DDs, yes, there’s a strong possibility. I definitely like the Zen Pro more than the Moondrop Illumination, but I also didn’t think the Illumination was nearly worth $800. Cayin’s new Fantasy was also, well, nothing more than a fantasy for the price it was intended to command. After hearing the Sennheiser IE900, I don’t think the Zen Pro has that same special sauce, but it’s certainly better in terms of raw tuning. I guess time will tell on this front.


I’ve been quite impressed with Dunu’s willingness to listen to the audio community, and this further cements my thoughts about that. Kudos to them for releasing the Zen Pro, and also for recruiting the industry’s top reviewers for their input.

Also, great feedback/impressions, @Precogvision


Yes, this is a great point - I’ve also been impressed with Dunu’s representatives posting on forums and explaining their products, e.g. why they use the components and the designs they do, to what effect, and with what benefits, limitations, and constraints.

I wasn’t keen on the Zen; I found it too bright for my tastes. I hope the Pro remedies this because it would be great to have a quality DD IEM on the market, for under a grand, that does timbre very well and that doesn’t have the peakiness or fatiguing quality of other DD IEMs (like the IE 900 or the Final Audio A8000, for instance).


It’s no secret that I love my dunu zen. Yet I agree with the assessment about brightness and tonal balance. I just overlook them in exchange for… bass impact and articulation as well as coherency.

@Precogvision Is there an IEM that does bass impact and articulation as well or better than the Zen, while improving tonal balance and addressing the brightness? (shouty for me on some music).

Thus far, in my limited experience, coherency has been important in all things. From B2 Dusk → Dunu Zen was a big step because it improved coherency across the board in addition to those bass parameters. Audeze Euclid had good coherency in everything but lacked the bass aspects.

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Ok Zen Pro is officially announced now. I participated in a Dunu-survery with Precog and others earlier this Summer and here are my results and impressions of the Dunu Zen Pro (pre-release unit)


Thank you for sharing your impressions. I’ve been excited by the prospect of the revised tuning of the Zen Pro because I very much disliked the upper mids through the treble of the Zen and found those IEMs to be too shouty and strident and, to a lesser extent, too piercing for me (and I like neutral/bright tunings, I have the HD 800 SDR).

I also appreciate Dunu’s transparency about how the changes they’ve made (their post on head-fi was excellent for explaining all this). I also like their methodology and willingness to solicit feedback from folks like you to revise the tuning. It’s cool that they’re responding to criticisms and making improvements to their IEMs. I fear, though, from your impressions, that the tradeoffs may be too significant - I look forward to checking out the Pro, though!


Got myself a pair of this and the Falcon Pro after demoing both on the CanJam show floor. Initial impressions from the show floor are still largely correct though I’ve found that, while listening at home it’s just a little soft-sounding or unclear stock. Don’t get me wrong, the tonality is almost perfectly balanced to me, but I just need the following 2 filters to complete the sound, with the first one making the most pronounced difference in tonality and sense of resolution:


  • PEAK: 3.5 dB, 6KHz, Q = 4.
  • HIGH SHELF: 0.8 dB, 10KHz, Q = 1.414

To my ear, and with the above EQ, note definition and (percussive/oral) impacts became tighter for all instruments, especially drumsets, pianos, violins, and the human mouth uttering consonants. Effectively, the stock tuning’s texture - from bass to mids to treble - is improved. I don’t think this exact EQ will work with everyone, but I think that means the Zen Pro’s tuning and technicalities is very good for those who want more fullness and texture with their neutrally-tuned ear-gain region.

EDIT: To clarify, I think I like those filters since the Prisma Audio Azul is a little more filled-in in those regions of the FR, with the Azul being the earphone with my most preferred tuning. I use Sedna Short Lights on both since they’re comfortable wide-bore tips with a good amount of grip and provide maximal treble extension compared to other eartips, to my ear. Graphs are normalized at 1.2KHz to reflect how my brain compares the two earphones:

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