Dunu Zen Pro Review Gear ipod touch 7th gen -> Zen Pro Pi2AES-> Yggrdrasil A2 -> Magni 3+ -> Zen Pro (great sound, but a little buzz) Shanling M6 Pro 21 -> Zen Pro NOTE: I used a Lunashops 7N 16 Core OCC Copper cable with the Zen Pro and the stock cable with the Zen. Both unbalanced. This may seem unfair but whatever I wanted to hear them with a cable I know and like. I have the exact same cable on my og Solaris so that’s good for that comparison. And Anyways Dunu didnt send the Zen Pro with its stock cable. Moving on… Comparison gear Pi2AES-> Yggdrasil A2 -> Lokius-> 789 w/ Sigma 11 LPS -> balanced out -> og Solaris Build Quality and aesthetics Outstanding. All plain metal construction looks and feels stunning. They’re pretty small iems so don’t draw attention to themselves, but if seen, they look good. They don’t stick out of your ears at all, they fit pretty deeply and are pretty well conceiled. You can almost lay down on your side on a pillow while wearing them Fit They have a pretty flexible fit due to their small size. They tend to want to fit a bit shallow, but I cram them into my ears and then they fit more deeply without issues. The nozzle is the perfect width and length to fit a lot of tips and fit them well. The nozzle is not too long so it doesn’t make the tips hard and un-conforming like many iems with overly long nozzles. Magnet Strength I don’t know if this is normal, but the magnets are so strong the iems will stick togeher and you can pick one up by the other along with the cable. They must be using pretty strong magnets. Sound Prelude It’s not often that I am impressed by an audio product, but especially a transducer in headphone format, be it electromagnetic, planar magnet, electrostatic, over ear, on ear, or in ear. There are few headphones of any kind that i like or can even stand. I’ve never been so surprised and impressed by a headphone of any kind before in my 16 year obsession with headphones. I was expecting something with a peaky response and mediocre technical abilities. Another peaky electrodynamic iem. I was very wrong. i am confident saying that these are the best iems on the market. I know, I’m an American and so i don’t know shit about iems. But I’ve heard enough to be able to extrapolate. The Dunu Zen Pro makes the Campfire Audio og Solaris sound like a $150 iem. From memory, they are on par with the og Focal Clear out of the Stratus. Or maybe better honestly. The Clears still sound like electromagnetics to me, albeit good ones. The Zen Pro just sound realliy really fucking good. These are the electromagnetic iems you all have been waiting for. This is the most positive review I’ve ever written for any piece of audio gear. I think these are going to be hugely popular. Sound In Brief The Zen Pro is extremely neutral from bass to treble, with a beautiful upfront midrange with excellent tonality that’s not recessed at all while at the same time not having any bumps or peaks in the upper mids. They have no peaks anywhere in the spectrum from the upper mids to treble. The lower midrange is flat too, they don’t sound thin at all, very natural. Very flat. They remind me of the Gaudio Nar in their FR. They also have no resonance that I can hear anywhere in the spectrum. This is a feat in itself especially for an electromagnetic driver iem, but at the same time, they have excellent technicalities. They’re fast, very resolving, dynamic and have a huge soundstage. Not quite as expansive as the CA Solaris but very close. Bass This is probably their only real weakness, but I'm using them from an ipod touch right now. Bass is about the same as the og Solaris. Not bad, it doesnt’ draw attention to itself as a problem, but it also doesn’t stand out as being extremelly capable. It’s a bit loose and one note smilar to the Solaris, but it gets the job done. I only notice it’s shortcomings when I focus on the bass an listen analytically. Driving them with the Magni 3+, the bass is much better. Tight, punchy, detailed. Still a bit one note but really pretty good. I imagine there are defnitely electromagnetic iems out there with better bass, but they will I imagine fall very short in every other way to the Zen Pro. Bass extension is excellent, they go all the way down. Just not super tight or punchy. With the Shanling M6 Pro the bass transforms. It’s really good. Impactful, tight, tuneful, layered, no bloat at all. it can feel skull shaking when the recording calls for it while being completely controlled. So the Zen Pro just needs good amplification for the bass to shine. Midrange Gorgeous. Uprfont, not recessed. Perfect tone and timbre. Rich and airy. Transparent. Super resolving. The og Solaris in comparison is quite hazy and recessed in the midrange, vocals sound glossed over and clouded. Which I never heard to this extent until hearing the Zen Pro. The Zen Pro is much more clear. NOTE: I’ve got the midrange turned way up with the Lokis for the og Solaris and it’s still recessed and hazy compared to the Zen Pro with no eq. Treble No peaks whatsoeer. Absolutely neutral. Great tonality. Cymbals sound brassy and metallic. Not a hint of plastic timbre. Sense of air is realy good. Very resolving for an iem. Resolution The Zen Pro are super resolving for an iem. More resolving than the og Solaris and a greater sense of clarity as well. I think they compete with many very good full size headphones in terms of resolution. The og Solaris sounds incredibly dull in comparison. Dull, lifeless, glossing over so much that the Zen Pro picks up easily. I can’t stand listening to the Solaris after listening to the Zen Pro, they make the Solaris sound like cheap BA iems. And they’re being powered by the best BA iem amp on the market with an LPS and the yggdrasil A2 behind it. The Zen Pro is really special here. Soundstage Really open and spacious. These don’t have an in your head sound at all. Sone of the best soiundstage I’ve heard from an iem. It’s also pretty well rounded, forward and back and up and down. Sensitivity and Noise/Hiss They’re not super sensitive, but they are sensitive enough that I pick up a buzz with the Magni 3+ and my Liquid Fire. Which is too bad because I’m not sure what desktop amp would be good for them. They’re dead quiet on my ipod touch. I think a good DAP is the way to go with the Zen Pro. Amp Synergy I don’t know what their impedance curve is like, I would expect it to be flat. But the bass seems to change a lot between amps. Out of my iFI Nano BL the bass is too much and loose and sloppy. Out of my ipod touch, Magni 3+ and Liquid Fire, the bass is perfect (neutral). I never plugged them into my 789 because that would be a crime against humanity. Comparisons VS og Solaris Same soundstage, or very close. The Zen Pro just walks all over the Solaris in terms of resolution, dynamics, tonality, timbre. they make the Solaris sound like a mediocre cheap iem in mid-fi territory. The Zen Pro with no eq has a more netural, upfront vocal range even when the og Solaris is heavily eq’d. The Zen Pro also has neutral treble, while the og Solaris is exaggerated and needs to be eq’d down. VS regular Zen with the Shanling M6 Pro (both iems at their best, though note that the M6 Pro has a slight up tilted FR,which I’m taking into consideration) The Zen has close to the same excellent tonal balance, peak free FR and lack of resonance as the Zen Pro, it just isn’t as techncally gifted. It’s still very good, but it’s kind of HD-650 ized a bit. Transieents are slower, dynamcis are softer, instrument seperation isn’t as good, soundstage seems more closed in. The difference isn’t huge to be honest, these are still great iems, but they aren’t competitive with TOTL full sized headphones like the Zen Pro is. It’s tuning is still damn impressive though. They are really nice to listen to. But they don’t take my breath away like Tom Cruise in a leather flight jacket. Tonal and FR differences It is a little peaky and resonant in the upper mids, just slightly. The Zen Pro is flat and clean. A guitar solo that winds up a little harsh on the Zen is fatigue free on the Zen Pro. The Zen also has more bass presence, and lower quality bass. Or if you read the description below from Dunu about the development of the Zen Pro driver maybe this is an illusion, but regardless, the Zen sounds bassier with lower quality bass. I will let others on the loaner tour review the Zen more thoroughly. Conclusion The Zen Pro, especially hearing it with the M6 Pro loaner which I just got back, has ruined all other iems for me. I’m seriously considering selling my 789 w/Sigma 11 LPS and all my BA iems and getting these and a good DAP. They sound so good. I could live with them as my only headphones esspecially with a good DAP. They sound equal to many TOTL full size headphones in every way except soundstage size of course. And perhaps imaging, but it depends on the headphone. There are few full size headphones with this technical ability that are also flat, neutral, clean and peak free. I prefer my modded orthos of course, but they’re big, more expensive, more heavy, and require modding. Bottom line, they are almost perfect iems with their only weakness being not having outstanding bass response without good amplification -and even out of the ipod it's not bad - it’s good it’s just not great but improves dramatically with better amping. And it extends all the way with no roll off. Inside scoop about the development of the Zen Pro driver from Dunu: The accessories, shell, etc. are all the same for the ZEN PRO; the anodize is a different color (now titanium grey), and hence the coating is a little thicker (and prettier in my opinion -- the black on the original felt a little flat to my eyes) 1. The driver has the same fundamental morphology (the W-shaped creased dome one of the most difficult parts to pull off on this driver because of the possibility of it cracking during the shaping process), but we wanted the area outside the voice coil (the rim outside of the hard crease) to be thinner. It wasn't previously achievable in our dome maker's previous production process (to keep the dome from cracking), but we entered a deep technical partnership with them to reformulate the Magnesium alloy such that it remains strong even when we thin out the edges. This reformulation accounts for a major part of the cost increase between the ZEN and ZEN PRO. Because we've been working with this partner for such a long time, we're fortunate they were willing to help us achieve these goals, despite the relatively low order volume. 2. The dome maker also took the initiative to reinforce the dome with an even thicker coating of our sp3-hybridized carbon predominant nanoDLC layer compared to the ZEN. Again, this DLC layer is different from something Campfire Audio uses. Because they needed to deposit DLC onto a polymer substrate, they had to rely on a lower temperature PECVD process. Because of our fully metal Mg alloy dome, we can use a higher temperature process that more easily yields a higher sp3-to-sp2 ratio. For strength purposes (a diaphragm needs not be slippery), an sp3-predominant composition is much preferred. 3. Because we were able to get the dome thinner without compromising on strength, the treble extension has improved as a product of a reduction in angular moment of inertia. 4. We didn't technically "reduce shoutiness". No acoustic damper at the spout was used. Instead, we pulled up the lower midrange in order to decrease the contrast between the lower and upper midrange. This was done by playing with the air gap between the voice coil and the magnet system. The end result is slightly more lower midrange detail, but counterintuitively, it sounds less forward, despite a small bump in response between 600 to 2000 kHz. 5. Pulling up this region also reduces the contrast between the bass and the lower midrange, which is one reason why some people feel dynamics are now decreased relative to the ZEN. However, for the bass, the driver is still displacing to the same degree on the Z-axis. It's just that the contrast between the bass and midrange is reduced, lessening the intensity.