Pros:
+ Great all-rounder
+ Overall tonal balance
+ Technical performance
+ Bass switch
+ Accessories
Cons:
– Not the most impactful bass
– Stock cable is stiff
Driver Setup: 6 Balanced Armaturs
Price: $580
Purchase link and info: HifiGo
Comfort, fit and isolation: Overall great.
Sources used: Topping L70, Shanling M6 Ultra, Hiby R6 Gen III, Fiio BTR7
Tips used: Stock cylinders – DUNU S&S
My usual test playlist with some of the songs used: Tidal
Table of Contents
Prologue – The SA6 bloodline
Before we dive right into the main course, we need to take a ride back to the year of 2020. By the last quarter, DUNU released the well anticipated SA6 – a 6 balanced armature IEM with studio reference tuning. Now, this event was previous to some of you joining this hobby and, in fact, it is even previous to me buying my first pair of “audiophile” headphones, but context is important.
At that time, which feels like a decade in audio years, the SA6 got a lot of hype built around it, making it go out of stock many times, and I honestly can see why, again, given the time context, but it was not until the end of 2022 that I got a chance to hear it and compare it to the, by then, newly released SA6 Ultra (SA6u, Ultra) – a collaboration between DUNU and Z Reviews.
The SA6 is a neutral with a bass boost that took a lot of tuning inspiration from the Anole VX – a great IEM still by today’s standards and top dog at its time. Its tuning main characteristic would be an early but flat pinna gain region until the treble area, but nothing goes past 8db in the frequency scale. Of course the performance of the VX is better than the original SA6, but it also costs 5 times more, making the DUNU a poor man’s VX.
Now, once again context is important, because my reality was different from the people when it was first released, as I only heard it 2 years later. I found the SA6 good, but not amazing, mainly due to the treble extension and how this affected its technical properties – the sound was too intimate and not that detailed for its price.
And then came the Ultra, that kept the best of the original, and fixed the worst. The upper mid-range got a polish, the mid treble gained presence and the extension finally showed up. By changing the internals and the tuning, everything just felt better, from top to the bottom – sure, the difference was not night and day, but it was enough for it to be extremely competitive and earn itself a top stop on the bracket.
But there was only one problem – the limited quantities. There were only 300 available units and a bunch of review samples – that I completely missed and had to pay full price for one. Needless to say that they lasted a couple of days, given Zeos’ popularity among the Youtube crowd.
So DUNU took a while to finish all the 300 units since they were handmade, but it was worth it, at least to those who got in time, while those who didn’t kept windowlicking it. SA6 Ultra was the IEM you wanted to try, but you couldn’t buy.
And then the news came: SA6 Mk2 (Mk2) was about to get released and was not limited, but rather improved and cheaper. Or is it?
Accessories and Build Quality
The DUNU SA6 Mk2 clocks in at around $580 and just like any other DUNU, would be a crime not to describe what comes in the box, given they are probably one of the best brands in that department, regardless of the price.
I do have to confess I found the box the less premium looking across all the other DUNU sets I’ve held – the looks and the internal foams feel more mainstream than I’m used to. The usual leather carrying case has also been replaced by a blue shell-style storage case, with an orange border on top and bottom that surrounds a mosaic with their engraved logo. While I enjoy the safety and space this case brings, it is nowhere near as portable as the previous versions – and if costs were to be cut, I would rather have the same old case but using textile instead of leather, like the one found on the KIMA or FP/ Vernus.
My nitpicking goes on into the cable section, but this one is transversal to the Ultra as well, as they share the same exact cable. The Hulk Mini is not my favorite cable in the world. Do not get me wrong, it is extremely well built and the Q-Lock terminations are still the best I’ve found, but my nitpick resides on its stiffness. Again, to cut costs, in the Mk2 version there’s no 2.5mm termination included, but rather just 3.5mm and 4.4mm.
Moving on to the tips, there’s a great arsenal inside, from various types of silicone to foam tips, including the newly acclaimed S&S cylinders. From the Ultra version to the Mk2 the changes are minimal. The requested Dekoni foam tips by Zeos are no longer present, but instead you get S&S in XL size – which is a trade-off I would do everyday, given I’m using them with this set but I couldn’t with the ultra because L was too small.
The rest of the accessories are the same as usual, as per DUNU’s standard: a great quality 3.5mm to 6.35mm adapter, an airplane adapter, a cleaning tool and paperwork/warranty.
Now, with that out of the way, it is important to note that even if the Ultra shares the same shell as the OG SA6, the Mk2 does not. The Mk2 is slightly bigger and adopts a more “custom” shape. As always, YMMV but I’m pretty certain that people with very small ears will prefer the first iteration, and people with bigger ears can go either way. As for me personally, I do prefer the second version and it gives me better stability and passive isolation – which is outstanding on its own.
The see-through resin shells on the Mk2 are outstandingly built but the faceplates have a different approach than the previous iterations, using a more orangish wood pattern. In the larger end of the IEM (the one that faces the back of your head), there still can be found the easily accessible atmospheric switch, which raises the bass shelf – a characteristic present on all three version, but with different results on the Mk2, as we will see next.
Sound
Disclaimer: All the critical listening was done through my Topping L70 fed by an iFi Zen DAC V2. All sets were volume matched to 75 dbs @ 440 Hz using a decibel meter.
My frequency response graphs are measured using a clone IEC-711 coupler, using stock tips matching the resonance peak at 8k Hz whenever it’s possible. As per usual with this coupler, this resonance peak is usually a coupler artifact (non-existant to the ear) and the measurements after it may not be totally accurate. If you would like to see or compare the graphs for this set and many others, you can do so on my squig.link database.
As hinted in the prologue and just like its older brothers, the SA6 Mk2 is a neutral with a bass boost with the flat pinna gain region à la Anole VX – when the atmospheric switch is off. DUNU has clearly heard the feedback during the last few years about the switch, as everyone and their mother kept it on. Different from its brothers, the current iteration takes a step further: the new baseline (switch off) is approximately the same as the previous with their switch on, and lets you raise the bar if you wish to.
Given all that, the SA6 Mk2 gets its first value point – two tunings for the price of one, – but for a matter of simplicity, I will be reviewing the SA6 Mk2 with the tuning switch off, until later where it gets mentioned again.
Atmospheric Mode: OFF
Tonality
The overall tonality of the SA6 Mk2 is still on the warmer side, thanks to the 9db bass shelf @ 20 Hz, that only corrects itself past 300 Hz. I’m a public defender of this kind of approach on drivers that are too snappy and light (read: balanced armatures and planars), as it compensates for their lack of “weight”. When done right, you end up with a fast present bass, without severe bleeding into the mid-range, and the SA6 Mk2 does it.
“Limit To Your Love” by James Blake displays a very capable sub-bass extension and rumble, allied to a snappy attack and decay, removing any blunt between notes. While switching gears for Deadmau5’s “Hypnocurrency”, the (in)famous BA bass becomes more evident – it is good, but if you are someone who lives, breathes and eats bass, none of the SA6 versions will be for you, as it lacks some of the physicality or elevation that most bassheads seek out.
Transitioning into the mid-bass, the tonality is pretty spot on for bass guitars and kickdrums. Ted Poor – To Rome has a perfect balance of presence and physicality, without being overly blunt, like happens with some DD drivers that overextend their shelf, thanks to its speed and fast decay. At around the 3:58m mark of “Tendinitis”, the SA6 Mk2 shows its claws during Luke Holland’s kickboxing match with the double pedals, leaving pretty clear when he presses and releases them. Now, on a less than great note, the impact and texture could use more work – as most BA Woofers could, – especially for those who come from other DUNU’s sets like the Zen or the Zen Pro.
Now with that out of the way, let’s delve into the stars of the show. The lower-midrange of the SA6 Mk2 is one for the books. The male vocal placement is stellar without mushing the vocalists with the rhythm instruments. Allied with great separation and layering, the replay of “So So”, “The Look” and “Reptilia” have not much to be added than my complete seal of approval, as you can clearly distinguish between all the instruments. Even on more chaotic passages like Radiohead’s “Bodysnatchers” (starting at around 3:30m), the distinction is still evident and the vocals still pop out.
Do keep in mind that the SA6 Mk2 has a touch of wet timbre, as being the opposite of dry (Harman tuning is a great example, like the Variations), so the lower notes of pianos won’t feel thin but neither will the higher pitched vocals. Speaking of those, the upper-midrange might look wonky in the graph, but there’s a reason for this approach. No matter what you throw at flat pinnas and how much you raise your volume, this tuning never gets shouty or shrill – even on Sia’s piano version of the “Chandelier”, which becomes borderline tolerable.
The consequence of these flat out pinna gain comes with more neutralish and less bite in the female vocals, when compared to tunings with a peak in this area. This effect can be noticed on “Flowers” by Miley Cyrus, where despite her timbre and microdetails being on full display, her higher pitch notes don’t stand out as much as other sets. Speaking of female vocals, one of my favorite replays across all the days I’ve spent with the Mk2 so far is when listening to “Snow On The Beach”. The separation and harmonics are just spot on, while the back vocals just float around you.
The “flat” approach to this range also translates into the treble region, minus a small dip around 6k to reduce fatigue. Flat trebles are one of my new favorite things and for a reason. While small dips and peaks in this area give a better sensation of depth and separation across the board, I find myself enjoying this flat style a lot nowadays. Its impact is very noticeable on cymbal strikes and electric guitars, giving them the required energy without changing the timbre. The live version of “The Speedwalker” is a great track to showcase this effect, where everything just sounds correct but Nate Smith’s drum kit (starting around 1:35m) is just to die for. I attribute this effect to the lack of major dips in the mid-treble and also the boosted extension region, that gives so much air to the live performances, teleporting you there.
Technicalities
If I commended the tuning, the technical chops of the SA6 Mk2 are nothing to sleep on. The stage is wide but most important, feels deep – that when allied with its good separation and slight warmth, turns a mid-range heavy track into a pot of honey. To cover that fact, the transient sharpness and overall speed driver speed make sure nothing feels blunt – at the cost of a not so great timbre due to the fast decay.
The sheer detail is good at this price level but the star of the show is the coherency between the drivers. The music just feels coming out of one big driver instead of six separated ones, from top to bottom. The weakest link of the technical department are the macro dynamics which come out as just average.
Comparisons
DUNU SA6 Ultra
As far as the competition goes, I do find the SA6 Mk2 to be in pair with my favorites around its price range. Needless to say that a comparison with the SA6 Ultra is inevitable but I will cut it short for you.
Regarding sound and by splitting hairs, the SA6 Mk2 has a more refined sub-bass response and treble extension, but also more elevation on these, tilting towards a U-shape more than the Ultra did. This also means Ultra mid-range is more prominent (read: very small differences) than the Mk2. The treble extension and different internal tubing seem to take the Mk2 technical chops half a step up in the imaging and sheer detail department vs its predecessor, but the Ultra eventually will sound more natural to the ear if you listen close enough.
Shuffle all that and you get around 95% of the same IEM with a different shell and different tuning options, but it is still what it is. For me personally and subjectively, I do prefer the Mk2, but they are close to twins.
XENNS Mangird Top
Based on the Harman target, the Mangird Top travels in the opposite direction than the SA6 Mk2, tilting brighter and thinner due to a small recession in the lower mid-range.
Without getting ahead of ourselves, firstly we must analyze the bass section differences between the two. While the SA6 Mk2 has moderate impact and presence to it, the Top is boomy and way more present, being very evident on tracks such as “Backseat Freestyle” but also having a better physical rumble on lower frequencies.
Other than that, the whole mid-range and treble feel more refined and natural in the Mk2, thanks to its warmer tonality and more evened out treble response, while the Top exhibits a more prominent upper-midrange but darker mid-treble and lesser extension.
The technical chops are pretty close overall, with the top showing an overall bigger clarity related to that mid-bass dip and the Mk2 being way more coherent.
Atmospheric Mode: ON
As mentioned before, all the SA6 family comes equipped with an atmospheric mode switch in the back of the shell, easily reached with your nails without the need of removing the monitors from your ear. In the case of the Mk2, the regular bass shelf is already at the same level of its predecessors, therefore having a 2 db boost over them in this mode.
On paper, this might not seem much, but given it affects all the bass shelf, lower mid-range and some of the upper mid-range, the overall tuning is affected, despite ceteris paribus. The neutral with a bass boost gives birth into a more L-Shaped or U-Shaped type of frequency, depending on the track and your personal hearing extension.
Overall, the tuning gets warmer and the bass way more prominent, resulting in a more tastefully “musical” set, but sacrificing a smidge of clarity for it, resulting from a more elevated mid-bass. During “Lost My Treble Long Ago”, Joe Dart’s bass guitar takes the spotlight, along with Nate’s pedals and toms, both more emphasized than the electric guitars. The same effect can be heard/felt during Polyphia’s sub-bass pads on “Playing God”.
Now, since the rest of the tuning was kept the same, I won’t repeat myself rather just “add the warmth” to it, which efficiently works due to the flat treble response and energetic extension. In short this has a positive impact on male vocals but the female vocals also get thicker and loose bite. Technicalities also remain the same, minus the smidge of microdetail that gets lost due to the loss of clarity.
Symphonium Meteor
Nowadays, especially in this price range, it is impossible to mention this type of tuning without bringing out the stellar Symphonium Meteor. When comparing both, the result was pretty obvious right from the get go. The Meteor just does it better, period. Despite having close to the same bass shelf, the impact is better and the texture runs circles on it. The Mk2 still has better mid-range, due to the late pinna gain rise in the meteor, translating into better vocals and pianos. As for the treble, they are more alike than so, especially in the extension segment. In the technical department, the SA6 Mk2 also takes the win by a small margin, especially on stage depth and detail, while the Meteor feels more dynamic although less coherent.
The verdict
By the time I got the SA6 Ultra on my hands, their stock was already gone for good and while I praised it to whoever asked, I did not get a chance to hype it because, once again, it “was the IEM you wanted to try, but you couldn’t buy”.
Now the tables turn and here we are, having a $20 cheaper alternative with the option to change the flavor as you please by pressing a switch, increasing the value of this set immensely. Given that and all the words above, it’s my pleasure to easily recommend the SA6 Mk2, joining the Symphonium Meteor and Magird Top as my current multi-driver favorites around this price range, for different reasons.
For those that already own the Ultra, I do recommend holding onto them. Both versions are very alike, unless you are buying it for the Atmospheric tuning, but then again, Meteor exists. Other than that, I think DUNU finally hit the jackpot that they are now back in the spotlight. Touché.
If you would like to see how this and other sets rank against each other, you can do so on my spreadsheet database.
Thanks for reading!
nymz reviews 
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