DUNU SA6 Ultra

Introduction​

By the time of writing, you should have known about this 300 units limited edition monster of an IEM. If you still don't, let me do you the honours by introducing you to this beauty, the Dunu X Z Reviews SA6 Ultra. Dunu has collaborated with youtube audiophile enthusiast - Z Reviews to make a limited run of a retuned (original) Dunu SA6. With all the hype that the original Dunu SA6 boasted previously, this retuned version (will call it the SA6 ultra from now onwards) had gained much attention, with Dunu managing to sell all of its 300 units in 2-3 days, which was no surprise to anyone including myself. Luckily for me, I managed to snag a pair of the SA6 Ultra on the second day of release, grabbing the 243rd set.

As you can tell from the images taken by yours truly, mine came with the blue faceplates on both sides as requested (although I kind of wished I had gotten the "Both Red" option instead).

Information​

Driver setup: 6 Balanced Armature (BA)
Price: US$599.99
Connection: 0.78mm 2-pin
In Box:

• Blue "DUNU" carrying case
• DUNU SA6 Ultra IEMs
• DUNU Hulk Pro mini modular cable + 2.5mm, 3.5mm, 4.4mm L-shaped interchangeable head
• 4x DUNU blue silicon tips
• 3x DUNU white silicon tips
• 4x DUNU S&S tips
• 3x Dekoni foam tips
• 3.5mm-6.35mm adaptor
• Cleaning brush (weird since lacking in nozzle grill)
• Certificate and a manual

Comfort and Fit: Fits well, not painful over long sessions and great isolation
Tips used: Spinfit CP100 (M)
Source: Ifi Zen DAC v2, Tempotec E44

Case: Fits in one hand completely, made out of leather. Zip keeps getting caught on the inner sleeve and a bit stiff. Gets a 7/10 from me for the case.


Cable: The included DUNU Hulk Pro Mini cable is really nice, feels light, strong and durable. My only nitpick would be the L-shaped termination as I prefer straight termination, but other than that, no complains. Gets a 9/10 from me for the cable.


Packaging & accessories: Despite the underwhelming unboxing experience, I highly rate the packaging of the SA6 Ultra - small, compact and filled with a bunch of tips (14 tips!), I am spoilt for choices but I will be sticking true to my roots by going back to the spinfits as always. Not only that, its small carbon footprint packaging gets a green thumbs up from me. They even included a 3.5mm-6.35mm adaptor. Gets a 10/10 from me. Good job DUNU!

Sound​

Bass​

Bass is the category that the SA6 Ultra does not compete well in. Having an all BA configuration, there will not be the punch, slam or rumble that you might want if you are a basshead or someone who prefers a bit more bass. However, the texture and cleanliness of the bass is well executed by the SA6 Ultra. As you know, the SA6 Ultra also has a switch to increase the bass region by +1-2db when in the "ON" position. In my opinion, the switch hardly made any difference, making the bass frequency of the SA6 Ultra a bit louder and more boomy. For me to even feel somewhat satisfied, I had to turn on the "TRUEBASS" on the ifi zen dac v2 and turn the switch to the "ON" position. Only then did I start to experience the rumble on certain tracks.

Mids​

Mids are so well done on the SA6 Ultra having a little warmth to its presentation. Any track that I listen to is just so captivating and immersive, though it does sound a TINY bit artificial at times. Instrumentals just bring so much liveliness and makes me feel passionate about playing instruments again. Vocals are well presented on both male and female, being forward, rich and detailed without sounding harsh or peaky. Just absolutely amazing.

Treble​

The highs are also full of quality. Airy, detailed, and just pure effortless. No weird peaks. No harshness. No sibilance. Everything is well represented and it is not fatiguing compared to something like the Sennheiser IE600 or LetShuoer S12.

Technicalities​

Nothing exceptional but nothing poorly done. Everything is above average from soundstage, imaging, details and dynamics. Just overall really well done. If I were to pick an attribute that stood out, detail retrieval would probably be the one that shines when listening to the SA6 Ultra. This can be both a pro and a con however, as poorly recorded and mixed songs are torn apart by the SA6 Ultra, making them very obvious.

Personal​

I pick up the SA6 Ultra when I am looking for something quiet, when I want to play some background music while studying, or when I am feeling emotional (ahem, Taylor Swift). Subjectively, with a neutral and not so fun presentation, I don't see myself picking the SA6 Ultra as often as I'd like. Objectively, these are really well tuned and executed. Again, well done DUNU! I look forward to listening to more IEMs from you guys in the future.

Test Tracks​

At 0:48 to the end of the song, when Justin or Khalid starts singing with the thumping bass, it does feel a bit lacking and I wish there was more punch and authority in the bass. However, Justin's and Khalid's harmonious voice comes out cleanly and the instrumental sounds well represented.





Everything comes off very cleanly except for the bass, again, it lacks the strength to give this song the impact it was intended to have. Billie's vocals are really smooth and clear though.






The piano, the flute, the harp, the cello, the violin, EVERYTHING is just so well replayed. Well mixed and it just makes me want to cry. Makes me feel like playing this song on the piano now...



Again, just a very clean replay. Immersive and cohesive. I just want to cry...Oops, I cried. The SA6 Ultra just excels in acoustic, soft, and calm music and it just brings life to them. Yes, I am Chinese, let me just listen to my Chinese songs.



Honestly thought that this IEM would not have played this song well, but here it comes to surprise me again. Male vocals come off so cleanly, the scream at 0:35 is just so well done. Chorus doesn't sound messy despite having so much going on.



The SA6 Ultra didn't execute this song very well. Generally, I would dance to this fun and groovy song but due to the lack of power that the bass has, it really doesn't allow this song to shine with its amazing bassline throughout the track.

Conclusion​

Is this the best IEM that $600 can buy? Well, it is definitely up there in its price bracket, facing against IEMs like the Sennheiser IE600s, Xenns Mangird Top and Moondrop Variations. Despite being not the most fun or exciting IEM, with its focus on a neutral, detailed tuning, it really allows acoustic, quiet songs to shine. However, poorly recorded songs or fun songs generally become dull and misinterpreted. However, this is a must try or must buy (if you get the chance). For me, it will definitely stay relevant in my collection for a long time for sure.

Well, there you have it. Quite a controversial take I'm sure.

I was actually quite smitten with the SA6 Ultra at first but I became quite quickly cognizant of the cons, souring the experience.

If this was ~$350 then we could have a serious conversation with a lot forgiven.

Cable and fit are God Tier

DUNU joined hands with Zeos from Z Reviews for a limited edition run of a new version of SA6, they named it the SA6 Ultra. With only 300 units made available, the SA6 Ultra actually went out of stock in just 2-3 days after release. I was not surprised at all. After all the hype that the OG SA6 had, 300 units were nothing for the SA6 Ultra. I managed to get my hands on a unit. The beautiful SA6 Ultra, one of the only 300 units ever made. Honestly, the pair actually sounds quite good. I personally never got any chance to audition for the OG SA6, but this SA6 Ultra impressed me with my very first session with the pair. The day I received the pair, I was kinda busy and thought let’s give the pair a few songs(just out of curiosity). I ended up having a 2-2.5hr session in the very first go. Even then I had to put it down to complete some pending work otherwise it would be a long long time. Well, today I am going to write my impressions down and share them with you guys.

About DUNU SA6 Ultra:-

The newly redesigned version of the SA6 houses the same 6BA per side driver configuration as the OG model. It is said to have got a slight change in tuning with the help of Z Reviews. It now has new shells with colorful wooden face covers and transparent resin cavities. DUNU has also redesigned the stock cable for the SA6 Ultra. It now comes bundled with their new Hulk Pro Mini cable with a patented Q-lock modular plug system. A lot of technical banter has been done, now let’s begin with the package and contents.

A Short Disclaimer:-

I received the SA6 Ultra from HiFiGo for a review tour in my country. Rest assured, all the impressions made in this blog are completely my own based on my own experience with the pair for about 7-8 days. I would like to thank HiFiGo for providing me with the sample, you can check out more information on their product page here. Sadly the pair has been sold out, so you can not buy it anymore unless you can score yourself a deal on the pre-loved market.

https://hifigo.com/products/dunu-x-z-review-sa6-ultra-iems

You can also read my review on the Gizaudio Website by clicking here.

Unboxing & Accessories:-

I have been a fan of DUNU’s package design. Previously, I had the DK3001 Pro and the EST112, both came in quite a luxurious packaging. SA6 Ultra on the other hand has got a compact but beautiful-looking package. It has a multicolored outer cover that has Studio SA6 Ultra branding on the front. From what I have seen before, DUNU gave such a compact package to their “SA” lineup. Inside, I have the pair with its stock cable in a blue DUNU-branded zipper pouch. Other accessories(multiple sets of eartips, cleaning tool, cable adapters, etc) are in a box at the bottom. That’s all about the package and contents of the SA6 Ultra, Quite a compact and colorful package.

Contents:-

>SA6 Ultra IEMs

>Hulk Pro mini modular cable.

>2.5mm+4.4mm+3.5mm plugs.

>Three sets of DUNU S&S tips.

>Three sets of DUNU Blue silicone tips, Three sets of DUNU White silicone tips.

>3.5mm-6.35mm adapter.

>Cleaning brush.

>Certificate and user guide.

Design, Build Quality, & Fit:-

SA6 Ultra is pretty compact and beautiful. The shells are made up of resin and have a compact build structure. It was introduced in three different color variants, Red-Blue, Red-Red, and Blue-Blue. I got Red-Blue colored shells for the SA6 Ultra, Red for the right side, and Blue for the left. Face covers have a unique texture on them. The pair simply looks well-built and beautiful. It takes 2-pin connectors with a recessed connection port. Not to mention the new Hulk Pro Mini cable is super good. I just got to try the Hulk Pro a few days back, it was quite stiff and heavy. But this new Hulk Pro Mini cable is light and not as stiff as the OG Hulk pro. The swappable connectors are easy to replace. All the housings on the cable have a premium brushed finish.

Personally, the SA6 Ultra fits me very well. The pair sits easily into my ears. In fact, this is one of the best-fitting IEMs I have tried so far. The shells cover the entirety of my ear canal mouth creating a good level of isolation from the surrounding noises.

Driving The SA6 Ultra:-

Pretty easily powered, SA6 Ultra doesn’t take a lot of power to shine its best. I personally tried the pair with my Shanling M7 and my HiBy RS2. Here are my findings with both combinations.

HiBy RS2+SA6 Ultra:-

Quite an organic combination over here. RS2 provides the SA6 Ultra with rich vocals with an organic tonality. The bass feels a little loose here, but overall pretty clean presentation. Mids and vocals are slightly forwarded here in this combination. Tonally, RS2+SA6 Ultra is a pleasing set.

Shanling M7+SA6 Ultra:-

M7 presents the SA6 ultra in a more neutral manner. The combination here has a more resolving nature than the RS2 combination. The detail level is also increased a tad bit here. Background sounds cleaner, the bass is tighter, and the overall dynamics take a boost with the M7. Tonally, it's not as organic, or as rich as the RS2, but it sounds more natural, more detailed, and more neutral.

Sound Quality:-

I have heard a lot of praise for the OG SA6 but never got a chance to audition for them. Personally, I was super excited for the SA6 Ultra, not for the tuning update, but for all the hype of the SA6 that has always been there. Many of my known and trusted persons in the community have praised the SA6 to the moon. So the excitement was obvious. And not to my surprise, the SA6 Ultra delivers a performance that captivates the listeners with just a few minutes on the pair. It sounds crisp, it has a quality resolution, it retrieves an amazing amount of details, and at the same time, it sounds inoffensive & smooth. Tonally the SA6 Ultra sounds mostly neutral and natural with the vocals presented in a little forward manner. Bass complements the other frequencies with a clean, textured presentation. It holds a decent amount of punch and rumble in the lower end. Midrange feels natural and accurate. Upper Mids are slightly forward and showcase wonderful clarity for vocals. Treble performance is simply amazing on the SA6 Ultra. The pair showcase a smooth, inoffensive treble with an airy and detailed presentation. Soundstage on the SA6 ultra is both wide and captivating. It has good width and depth but creates an immersive presentation with its forwarded vocals. Let’s move ahead and discuss different frequencies individually.

Lower-End, Bass Response:-

If you are someone who likes a lot of bass, a lot of punch, and a lot of slam, you might not find the bass of the SA6 Ultra to your liking. But if your preferences suggest a refined, textured lower-end performance, the SA6 Ultra will surely hit the right spot in your heart. It packs a decent mid-bass and a powerful sub-bass region. Bass heavy tracks such as Bad Guy by Billie Eilish, Limit To Your Love by James Blake, etc showcase a clean presentation with a clean sub-bass rumble. The bass region is very well controlled within its region and showcases a good amount of details.

Midrange, Vocals, Instruments:-

While writing this blog, I am listening to the Hotel California by Eagles for like the 10th time on the SA6 Ultra. It just sounds wonderful. The acoustic intro of this track is presented so beautifully and nicely that it sounds utterly charming and captivating. Both the male and female vocals sound rich and detailed. They have a clean textured presentation. Even at louder volumes, I don’t find the SA6 Ultra to go shouty or lose its temper at any time. Pretty amazing vocals IMO. Instruments sound airy and spacious in the midrange frequencies.

High-Frequencies, Treble:-

As I mentioned above, the SA6 ultra handles the High-Frequencies amazingly well. It delivers an airy, inoffensive, and detailed presentation. IMO it is one of the most detailed sets in its price point. I have heard the likes of Shanling MG600, Softears RSV, CA Andromeda, Sennheiser IE600, and a few more models that fall right in the same price segment, the SA6 Ultra trumps them with its amazing level of detail. Not saying that all the others that I have mentioned are bad or worse IEMs, it’s just the SA6 Ultra has a better level of detail retrieval than them. I don’t notice the SA6 Ultra going sibilant or piercing at any point.

Soundstage, Imaging, & Other Technical Parameters:-

DUNU SA6 Ultra presents a wide airy soundstage that has a good 3D holographic presentation. Imaging and instrument clarity is pretty good with the set. I find the SA6 Ultra to be quite competitive with other IEMs like Monarch MK2 that are priced above it in terms of technical performance.

All in all, I must say DUNU SA6 Ultra is a pretty impressive set that delivers a pretty amazing sound performance with a neutral tonality. It doesn’t overexaggerate or overpower any given frequency segment. What can be improved with the set? I will say a little more punch to the lower end would make it sound more fun and engaging. But I am honestly just nitpicking over here because the SA6 Ultra sounds wonderful as it is. Now it’s time for some track recommendations and their performance with the SA6 Ultra.

Bad Guy by Billie Eilish:-

One of the test tracks that I use to test for sub-bass. SA6 UItra handles this track well and presents the listeners with a powerful yet clean sub-bass presentation. You will be able to hear the track with utmost clarity and crisp details with the SA6 Ultra.

Janam Janam from the Bollywood Movie Dilwale:-

A regional track, kinda busy track as you can listen to a bunch of instruments and vocals. SA6 Ultra showcases its competence with its ultimate technical performance. The track starts with a beautiful violin followed by other instruments and vocals. This is one of my favorite tracks, it has different ranges of vocals, and the SA6 Ultra presents it well and showcases good details.

Someone You Loved by Lewis Capaldi:-

Beautiful vocals, SA6 Ultra reproduces excellent details and rich vocals in this track. Not to mention the beautiful piano present throughout this track. One of my absolute favorites, and SA6 Ultra presents it in the best way possible. Pretty captivating I must say.

Lose Yourself to Dance by Daft Punk:-

SA6 Ultra is a good companion for this track. It sounds punchy, crisp, and groovy. Must say, the SA6 Ultra complements different genres with its presentation.

Speak Softly Love by Yao SI Ting:-

For female vocals, this must be one of the best test tracks that I have in my library. SA6 Ultra presents this track with ultimate vocal clarity. They sound emotional and detailed, they have a rich tone to them. Pretty good performance!!

SA6 Ultra with Ambience Mode(Bass Switch):-

The ambiance mode enhances the mid-bass punch with the pair. It takes a very little toll on the detail retrieval as well but gives more punch to the mid-bass response. I personally like the SA6 Ultra more on the stock mode.

Now it’s time for some comparisons!!

Softears RSV vs DUNU SA6 Ultra:-

I recently had the pleasure to own the Softears RSV. I absolutely adored the set mainly for its lovely midrange. Here’s my take on these two.


>RSV’s midrange is lusher and richer than the SA6 Ultra.

>SA6 Ultra has a cleaner presentation throughout the frequency band.

>SA6 Ultra gives a refined lower-end while the RSV packs more punch to its lower end.

>Softears RSV lacks in terms of resolution and details compared to the SA6 Ultra.

>Soundstage for the RSV is more immersive, and more intimate, while the SA6 Ultra has a bigger stage presentation.

I personally loved the RSV a lot, especially for its midrange presentation. It still tops my list for rich vocals, SA6 Ultra on the other hand outperforms it in terms of staging, dynamics, and resolution.

Final Words for the DUNU SA6 Ultra:-

Every time I put the SA6 Ultra into my ears, it impresses me in a new way. When I first auditioned the set, I was more into its resolution and detail retrieval, but slowly I began to praise its vocals, and so on. It gave me so much listening pleasure that I actually listened to the SA6 Ultra more nowadays compared to my Thieaudio Monarch MK2. It’s better fitting, it’s close in sound signature with Monarch’s being a tad bit better here and there. From all the hype around the OG SA6, I was expecting the SA6 Ultra to be good, but this level of good is beyond awesome. I spent countless hours enjoying my favorite music with the SA6 Ultra over the past few weeks. SA6 Ultra is the top recommendation in my collection simply because of its outstanding acoustic capabilities!!

Prologue

I dove into the IEM rabbit hole about 3 years ago. In that time I've been fortunate to listen to over 20 sets ranging from $100-$700 (with a few outliers ). Among these earphones, the original (OG) DUNU SA6 stuck in my memory for having unusually good dynamics for an all BA set, excellent comfort, a relaxed natural tuning I could listen to all day long without fatigue, and the only unit I've come across with the 2 pin connection in a fully recessed socket. This last detail may seem strange to call out, but for gear that is known for portability, recessing the 2 pin socket adds significant security in preventing cables from slipping out or pins breaking from lateral forces.

Original SA6 (image credit https://theheadphonelist.com/)

So why would I sell such a great set? Every earphone has its strengths and weaknesses. For me the OG DUNU SA6's soundstage was very compact and the detail retrieval was about on par with sets in the $250 bracket.

The Announcement

Flash-forward a few years, and a well known YouTuber, Z-Reviews, creates a YouTube channel exclusive to IEMs. In his first few videos he casually mentions a plan to collaborate with DUNU on a re-tuned SA6. My ears perked up. A couple weeks later a few other reviewers, namely BGGAR and Gizaudio, got their hands on pre-released sets and their first impressions were overwhelmingly positive. In fact the 2 short comings I mentioned seem to be the main issues addressed by this collab. The catch? DUNU signed up to only make 300 units and the price hadn't been announced. Oh boy, such few units with high profile influencers backing it, these were going to go fast! I was determined, I scoured the internet searching for more information on the release.

HiFiGo, the exclusive online retailer for the SA6 Ultra, posted a "Coming Soon" page. You could select if you wanted the shells in blue & red (denoting left and right respectively), or both blue or both red. This is a welcomed change from the roll-of-the-dice colors you got with the OG set. I'm a sucker for natural wood, so I selected both red faceplates. And when you added the pre-released item to your cart....$9,999. My heart sunk. Would they really mark it up that much above the OG, talk about a money grab...What has the world come to!?!

A few days pass, and I receive an email from HiFiGo that the SA6 Ultra was going to be released within 2.5 hours and the first 50 customers will get a USB-C adapter for the modular cable. My hopes were slashed by the price but I figured I would keep an eye on the page. 2.5 hours goes by and I hit refresh. It looked the same. I refresh it a few more times and then, the update! The price was only $50 more than the OG!! I quickly placed the order, and within 72 hours all 300 units were sold-out. It turns out the $9,999 pre-release price was just a placeholder.

What's in the box?

The box itself is adorned with a colorful stripe pattern that manages to be both playful and mature at the same time. In Z-Review's video about the Ultra, he mentioned the artwork was made by one of his patrons.


Inside you get a blue DUNU carrying pouch that appears to be made of leather. The size is pocketable but a little large, and the zipper is pretty stiff. Maybe this will break-in overtime. Also inside the pouch is a small meshed pocket for accessories, a nice addition especially considering the modular cable.


The cable is what DUNU calls the "Hulk Pro Mini." It is well behaved with a bit of a rubbery feel. The connection points are all gunmetal brushed aluminum, and it terminates in DUNU's proprietary modular connectors. These attach to the cable through a 4 pin connection and lock into place with a slip sleeve. This locking mechanism is a great feature that is missing from most modular cables today. The cable comes with 2.5, 3.5, and 4.4mm terminations. HifiGO also threw in a USB-C adapter for being one of the first 50 orders placed! My only gripe is that the terminations have a 90 degree bend. I prefer straight terminations to ease hot swapping between sources and pocketing a DAP. There is also a 3.5mm to 1/4 inch adapter in a bag with a cleaning brush.


DUNU included 3 types of silicone tips and a set of Dekoni foam tips. I'm not a fan of foam tips, so those stayed in the bag. I was a little disappointed that DUNU didn't include my preferred black tips from the OG model. Of the 3 silicone tips that were included, the new is cylindrical grey style, aka "Stage & Studio" were my favorite. These provided the deepest fit, which improved isolation and treble response. In the end I tip rolled and landed on my favorite dual flange tip by CTM.


And of course the earphones. The faceplates are absolutely gorgeous. The red tone really highlights the grain accents of the stabilized wood. The build is just as good as I remember from the OG. It is a pseudo custom fit that is the most comfortable universal IEM I've tried to date. There is a toggle switch that can be actuated with a finger nail. It is there to add a slight amount of bass, but really has very little impact to the sound. I prefer a warm signature, so I keep this in the ON position. Also there is a small X shaped vent that prevents pressure build up. This is key for comfort during long listening sessions (I'm looking at you Moondrop S8). And of course, the recessed 2 pin socket remains . My only gripe is that the nozzle doesn't have a grill to prevent debris from entering the tubes. I am not sure if DUNU modified the OG's crossovers and filters, or if they are using unique BAs. I'm including some close-up shots that maybe someone can use to compare with the OG.

The Sound (VS MEST MK2)

Well BGGAR and Gizaudio were right. These are better than the OG SA6, by a large margin. I could get into describing how instruments sound natural, or how it has great extension and sparkle. But I find sound quality isn't absolute, it's relative. So here's a comparison with what has been my favorite set, the Unique Melody Mest MK2.


The Mest’s bass has better extension and rumble but is also a bit slower. The DUNU has good rumble but is more of a punchy bass. Mest is like a ported 15” subwoofer, while the Dunu is like a sealed 12” sub.

Midrange of the 2 sets are pretty comparable, with the Mest having a bit more weight behind notes and the DUNU having a little more energy in the presence region. I don’t like breezing over this section, but honestly both sets are balanced, detailed and just excellent.

Treble on both are outstanding. The Mest manages to produce a little more detail, but it feels segregated from the rest of the music. Like having tiny cymbals behind your eye balls . It’s a very unique experience. I’ve heard other EST sets, and the treble usually sounds a bit weightless. The Mest doesn’t have this issue, and if I were to guess it’s where the BC driver is really assisting. It’s a very unique experience but not the most true to life. The DUNU on the other hand is very coherent and accompanies the rest of the frequencies to make one common sound. It has great extension, providing excellent micro details and air.

Soundstage and imaging of both are very good, I think the largest difference is the Mest has a darker background (exaggerated space between instruments). This gives the impression of more pin point like imaging.

Build and fit of both are very good, but I find the DUNU more comfortable for long-term listening.

In summary I’d consider the Mest MK2 an amazing earphone and an audio enthusiast’s set. The Dunu on the other hand is closer to true audiophile gear. If they decided to mass produce the Ultra, I think it would be a major market disrupter. Similar to the likes of the Timeless, Monarch/Clairvoyance siblings, and the Blessing 2.