DUNU SA6 Review: Mid-Fi Maturity

Introduction

If you're mildly familiar with the ChiFi IEM scene over the past decade, DUNU may have been one of those brands you've heard but never really given any thought to. At least, that's the way it was for me. Yet in the last couple of years or so, DUNU has appeared back on the scene with a variety of new IEMs.

 

I was pretty curious about DUNU and reached out to them for a bit of a history lesson. To roughly paraphrase what their global director of business development Kevin told me: 

 

    "DUNU started as an OEM business incorporated in Taiwan, Hong Kong, and China back in 1994. From there, DUNU started to engage in audio forums like Head-Fi in the 2010s. But around 2015-2017, they had to shore up some business in China (N.B. which explains why they've been quiet over the last few years) before returning back to the global stage. Specifically, over the past three years, DUNU has invested heavily in R&D for Beryllium-based dynamic drivers. This is reflected in their flagship DUNU Luna and upcoming IEMs."

At any rate, the past year has been especially fruitful for DUNU as they've found runaway success with the topic of today's review: the DUNU SA6. Ironically, it doesn't tout a Be DD. Falling squarely in the mid-fi price range at $550, it's a 6 BA IEM with a single tuning switch for what DUNU calls an "atmospheric immersion" mode. Without further ado, let's get into the review. And make sure to check out the video version of this review on Youtube!

Disclaimer: DUNU sent me the SA6 for review in exchange for my honest thoughts. I do not get compensated in any other way. Shoutout to Kevin and Tom at DUNU for their time and providing me this opportunity.

What's in the Box?

The SA6 comes with a comprehensive set of accessories. It includes a fairly classy faux-leather zipper case, 11 sets of SS, S, M, and L tips, a cleaner tool, a 3.5 mm to 6.5 mm adapter, and DUNU's DW-03 modular cable that can hotswap between 2.5 mm, 3.5 mm, and 4.4 mm jacks. Personally, I'm not a big fan of the cable. It's a cool concept but the cable is on the heavy side for me and has a fair bit of cable noise. On the upside, it has little cable memory and the L-shaped jack is greatly appreciated in these modular-style jacks when the length of the connector can start to get unwieldy.

The IEM itself is rather small and very comfortable in my ears. Isolation is good. It has a single tuning switch at the top that thankfully does not require a SIM tool to flip. The shell is made of a translucent smoky resin with a strikingly gorgeous faceplate. These shells are apparently handmade and the faceplate is made from stabilized wood that you can get in many different colors. Unfortunately, it looks like the exact color and pattern you get each time will be random and unique. Gives it a very nice one-of-a-kind artistic feel in my opinion but you'll be rolling the dice a bit on what the final faceplate will look like. I think mine looks stunning and I've seen a few other beautiful pieces too, so good luck if you grab one!

Sound

My first impression of the SA6 was "yea, this is an all BA IEM". It's definitely not bad, just that it has that classically BA-like sound. After having done nothing but review hybrid IEMs for the past year, that non-dynamic bass timbre was quite noticeable. My second thought was that these IEMs sound very nicely balanced. It has a smooth, forgiving sound signature. Bass is at a comfortable level, mids are lightly relaxed, and treble has an odd balance to it that I'll get into. The tuning switch adds a slight 1-2 dB boost in the lower mids and bass on the ON position. Despite this minor bump in the low end, it absolutely has a meaningful effect on the bass response, going from a lighter punch to a weightier thump. 

Bass:

The bass of the SA6 is what I'd consider high quality BA bass. Where it lacks in a deep, bodied bass response seen from top tier dynamic drivers, the balanced armatures of the SA6 has that characteristically fast decay accompanied with a tight, reactive punchiness. What stands out about the SA6's low end response is how well controlled it is. In some of the tracks in my library, it can be hard to tell if the track itself is poorly recorded or if the IEM/headphone can't keep up with it. With the SA6, I never get the feeling that it fails to handle the track. What's more impressive is that the SA6 does this without compromising low end quantity. It doesn't need to rely on a lean tuning to as a way to capture that sense of control. The bass doesn't bleed into the mids and there's not a hint of muddiness or bloat.

There's a healthy amount of low end volume that lends to the overall balanced tuning of the SA6. On the stock 1 position, the bass of the SA6 is light and leans punchy, giving a it clean cut low end that doesn't sound sterile. On the so-called "atmospheric" ON position, that punchy bass takes on a weightier, thumpy type of sound that's a whole lot fuller. While this transformation isn't exactly dramatic, it definitely adds a different dimension to the SA6's sound that I suspect many people will enjoy. I personally prefer it on the ON position for more bass oomph to compensate for the BA nature of the SA6. My only complaint would be a lack of a substantial DD-like subbass rumble and impact. Otherwise, the SA6's bass response is nicely spread across the low end spectrum without sounding like it centers around the mid or upper bass. I've found that when some other IEMs that try for a fast, punchy sound or a deep rumble, they end up too pigeonholed in only the midbass or subbass and gives up the other parts of the bass range.

Mids:

The mids of the SA6 can be described as tonally pleasing and smooth. There's no sense of incoherency as the bass transitions into the lower mids. Notes are well defined. Tuning wise, while the SA6 certainly isn't lean, it isn't warm either. There's not really any elevation in the lower mids and there's plenty of upper mids to dissuade that notion. Speaking of the upper mids, I find it to be at a tasteful volume. Not too much that it sounds overly forward or shouty but not recessed that it's hidden or smothered. Vocals are well positioned front and center without a glimpse of sibilance. I don't detect any sort of peakiness that might put someone off. Instrument tone is excellent. Unlike the bass, there's no BA timbre here. Like most other great sounding IEMs, the SA6 has a strong midrange showing with little to nothing to complain about.

Treble:

The treble of the SA6 is pretty unique. It's non-fatiguing and easy to listen to yet it doesn't shy from being fully present in the mix. It's also very forgiving of poor recordings. Listening to hats and cymbals, the initial attack is partly muted while the backend sizzle has more prominence. It gives the illusion of having a lively and unabated treble without fatigue. Looking at the FR graph, it's easy to see what's responsible for this. There's a fairly large dip right at the start of the lower treble around the 5 kHz mark before recovering around 7 kHz. The de-emphasis on the lower treble and subsequent elevation of the mid treble gives rise to a clear presence that doesn't sound aggressive. This dip also has the added benefit of avoiding common pain points for sibilance or harshness. While I'm usually a fan of having crisp hats and cymbals, I'll give the SA6 a pass here. Though this tuning strategy does forgo some of that natural lower treble energy, instrument timbre is still mostly preserved. Other than the hats/cymbals, I'd say the other common instrument that's notably affected is the sharp crack of the snare. For the smooth, overall balanced tone that the SA6 strives for, its treble complements it very well. My only nitpick is that I wish there was more upper treble extension to give air and brilliance but that's a complaint for almost every IEM I've listened to.

Presentation:

Soundstage and imaging on the SA6 is on the good side of average. It's what I'd expect for mid-fi but nothing to write home about. Good width with a couple of steps in height and depth. Imaging is solid. Instruments are well separated and properly defined. Similarly, there's a bit of a layering effect that positions instruments such that they never feel like they're congested or fighting for space.

Resolution on the SA6 is about as good as its gets until you reach top tier levels. I'd say my only nitpick on the technical side is its slightly diminished dynamics. I do get a bit of a sense that soaring vocals or thunderous kicks seem to hit a bit of a wall at the very peak. But to be fair, this complaint extends to most every IEM except for the truly outstanding.

All in all, the DUNU SA6's technical performance and presentation sets a robust benchmark for mid-fi. Some of the keen eyed among you may have noticed that the SA6 tuning is rather similar to QDC's TOTL models, especially with the 5-6 kHz dip. Based on my brief demo of the QDC 8SH, despite the similar tuning, the SA6 is undeniably still a step down. While it's clear that the SA6 still has a bit of a ways to go before the throne of TOTLs, it comfortably stands its ground in the court of other great IEMs.

Should You Buy It?

Yes. The DUNU SA6 is simply a really good IEM. While it doesn't necessarily have anything that's particularly groundbreaking, every part of this IEM comes together beautifully for an experience that's well worth the $550 price tag. It even managed to surprise me in some ways. I didn't think I'd prefer the bassier ON tuning nor expect to enjoy this sort of treble tuning this much. And this may be petty but I do like knowing my SA6 is possibly the only one in existence with its specific color scheme and wood grain pattern.

From what I can see, the DUNU SA6 faces two threats. The first is the Moondrop Blessing 2. While I haven't heard it, my guess is that the SA6 won't beat it terms of sheer price/performance. Though you could always make the fit and comfort argument I suppose. The second challenge is that the SA6's relative lack of a "special sauce" may make it susceptible to being supplanted by similar IEMs at better price points in the future. That said, whether those hypothetical IEMs will ever exist is a question in itself. And it doesn't detract from the value that the SA6 brings to the table. In fact, to put things in perspective, I'd probably get a DUNU SA6 over the Thieaudio Clairvoyance. Between the price and the fit, the SA6 is better value for my money (though the Monarch is still safe).

To conclude then. The DUNU SA6 is an easy recommendation at $550 for almost everyone looking in that price range. This is an IEM that has rightfully earned its praise across a multitude of reviews. Though the hype train may be gone at this point, I'm glad I had a chance to toss my hat into the review ring. I hope DUNU keeps up the good work and continues to release other great IEMs. Only time will tell if that opening story about their R&D efforts was just marketing speak or the seeds of a great future.

And perhaps the greatest praise I can give the DUNU SA6 is that when the pandemic ends, it may be the new daily driver to replace my beloved Sony MDR-EX1000. Ultimately, audio is all about compromises and the SA6's set of pros and cons might finally be the one that outbalances the EX1000's.

Written by: Fc-Construct