HiFiMAN Deva Wireless Planar Headphone - How does it compare to the Sundara?

Review written by Andrew Park (@Resolve)

Review unit provided by HiFiMAN for evaluation

Introduction

When I got a chance to speak with HiFiMAN CEO Dr. Fang Bian at CanJam NYC this year, he told me that wireless is the future. Being firmly rooted in the audiophile enthusiast community for many years now, this statement made me think to myself, "eventually, but we're not there yet". I think he's right about this, but up until now I haven't heard a headphone that sufficiently delivers the kind of audiophile sound I want in a wireless headphone. Now comes HiFiMAN's latest product, an entry-level (for their lineup) wireless open-back planar magnetic headphone. I imagine that the goal with the Deva is to be somewhat of a proof of concept - that you can in fact have audiophile level sound quality with the convenience of a wireless design. And so I've approached my review of the HiFiMAN Deva with the question of whether or not that's possible.

To answer this, I've been comparing the Deva to the slightly more expensive yet highly regarded HiFiMAN Sundara to see where the differences lie. I think for many who might be looking at the Deva, the Sundara is close enough in price that it's worth asking how important wireless functionality is, and so the question becomes what do you lose (if anything) by going for it.

Note - for this evaluation, I used it both in wired and wireless mode (LDAC).

Specs

Deva

• Driver Type: Planar Magnetic
• Design: Open-back
• Impedance: 18 ohms
• Sensitivity: 93.5 dB
• Weight: 360g
• Connector (cup side): one 3.5mm plug

Bluemini

• Amp Output 'in fact': 230mw
• Amp Output 'in theory': 1125mw
• SNR: 95dB
• THD: <0.1% @1W/1Khz
• Bluetooth Codecs: LDAC, APTX-HD, APTX, AAC, SBC
• Resolution up to 24bit / 192kHz (USB), 24bit / 96kHz (Bluetooth)
• Microphone

Sources

• iFi Pro iDSD -> Cayin IHA-6
• iFi Pro iDSD -> SPL Phonitor X
• Mytek Liberty DAC
• Auris Audio Euterpe
• Earmen TR-Amp
• iFi iDSD Micro Black Label

Build, Design & Comfort

For the most part, the Deva feels well-constructed with solid materials. I think HiFiMAN have taken some of the criticism regarding build quality to heart, since the yoke structure for the Deva is all one piece. This means that there are fewer potential failure points. The one area where I have to still be critical is that the place where the arms connect to the headband feels flimsy as they wobble back and forth. I imagine this is actually intentional though because this also allows for a bit of cup swivel, alleviating one of my only complaints about HiFiMAN's excellent Sundara.

As a result, the HiFiMAN Deva is reasonably comfortable for long periods of time. The headband uses thick and comfortable padding, and while I normally prefer suspension style headbands, the Deva is lightweight enough that there are no issues. Well done HiFiMAN.

Performance

The HiFiMAN Deva uses a planar magnetic transducer, that I’m told isn’t actually based on any of HiFiMAN’s previous designs. There are bound to be similarities across different models, but my understanding is that the Deva’s driver is new. For anyone wanting to know more about planar magnetic headphones, you can learn about them here, but the main thing to keep in mind is that for planars, the pistonic air-moving motion of the diaphragm is created by a conductive trace that’s physically on it, rather than by a moving voicecoil behind it.

In any case, the Deva uses a double-sided magnetic array, which is surprising considering it's so lightweight. What’s interesting here is that I would have thought one of the reasons for a new driver design would be to make it highly efficient and easy to drive for use with the small Bluetooth receiver, however when you use the Deva in wired mode, it actually requires a surprising amount of power (and current) - enough that I wouldn’t run it from a phone or a low powered amp. 

This means that the Bluetooth receiver DAC/amp combo (which does have LDAC functionality) packs a surprising amount of power behind it as well. HiFiMAN call this device "Bluemini", with the added phrase "small but mighty", and that's an accurate description. I’m also told that a lot of design efforts went into making the Bluetooth receiver, and it works flawlessly. So if anyone is thinking that there would be a performance loss when it comes to using the Bluetooth functionality, there’s no significant difference when using LDAC.

Check out this video interview from CanJam NYC to hear what HiFiMAN CEO Dr. Fang Bian has to say about the Deva and wireless headphones in general:

Perhaps the most interesting part of the Bluetooth receiver's design is that it attaches outside of the cup. There are serious acoustic benefits to designing it this way, since more traditional designs often have to make certain accommodations inside the cup to incorporate wireless functionality into the headphone. Doing so normally introduces certain concessions that lead to having to change the headphone's design in some way that wouldn't necessarily be as acoustically optimal as it would be otherwise. This means that in theory, with HiFiMAN's Bluemini receiver, many other headphone designs could be made wireless in future products. For me, what they end up doing with this technology in the years to come is maybe the most exciting part, since it means that even flagship headphones could potentially take advantage of this tech.

Detail Retrieval

For detail retrieval, or as I like to call it “image clarity”, the Deva isn’t quite where I’d like it to be at this price point. Recognizing that the Deva is wireless capable however means that we have to reconsider the landscape for where the Deva is priced at, and so if I imagine that it didn’t have the Bluetooth receiver the price would be a lot more appropriate.

The main issue I have with the Deva’s detail retrieval has to do with some slight grain in the treble, and perhaps a less clear midrange due to some unevenness around 800-1khz. The treble etch I hear is very minor, but it becomes obvious that the Sundara is noticeably more detailed in the treble (and not just for its tonality). This can occasionally cause consonant sounds to come across with a slight harshness to them. It’s not strictly sibilant, because it doesn’t have a substantial elevation in that region like certain Beyerdynamic headphones do, but I still hear the ‘S’ ‘F’ and ‘T’ sounds as less clean than the way I hear them on the Sundara. Apart from that, the Deva sounds very similar for detail retrieval to their older HE-400i (one of their older headphones), or perhaps HE-4XX from the Drop collaboration. These both can be found at a more modest price (when the HE-400i is on sale), but I think that's likely what the Deva would cost if it didn't have the wireless functionality as mentioned.

For bass and mids, this difference in detail is maybe not as noticeable but I think that’s just because treble frequencies often have an easier time of indicating these issues. Once again it has to be said that this concern is only in relation to the Sundara, which isn’t a wireless capable headphone. So if we compare the Deva to other wireless headphones, things start to look a lot better. The one consideration for this area is that at $100 more, the Audeze Mobius (also wireless) has noticeably better detail retrieval and image clarity, and that’s also a closed-back headphone.

Speed

For speed, the Deva once again isn’t quite on the level of the Sundara. It doesn’t have that strongly recognizable ‘plucked’ quality I typically associate with planars, but it’s also still tight and well-controlled sounding. I don’t think anyone is going to have issues with fast transients and busy passages either. I think a more fair comparison here is once again with the HE-400i, and in fact I get the sense that the Deva is fairly close to that headphone for technicalities in general.

Dynamics

Unfortunately I don’t find that the Deva has much for punch and slam (we might call this ‘macrodynamics’). But it does actually sound slightly bass elevated, specifically in the mid and upper bass. This means that it might impart the perception of punch and slam but really it’s not the same as what some dynamic driver headphones at this price are able to deliver.

But I’m also a bit surprised because I found the Sundara to have a bit better punch and slam than the higher end ‘egg-shaped’ planars from HiFiMAN like the Ananda and Arya, and I suspect this had to do with the fact that those headphones don’t have a uniform fit around the ear, where as HiFiMAN’s more rounded planars do. Speaking with a number of engineers on the subject, it seems pad seal is one of the parameters for this ‘slam’ quality, and due to the Deva’s rounded shape, you do get a decent seal. So maybe its lack of punch is the result of other parameters that are responsible for the more lightweight design.

In any case, if you’re looking for a punchy sounding headphone with high excursive ability, it might be a good idea to look elsewhere, or perhaps go up to the Sundara as well.

When it comes to what some audiophiles call ‘microdynamics’ or granular volume intervals (I typically associate this more closely with detail because I find it contributes to the experience), I find that the Deva doesn’t stand out particularly strongly, but I do think it performs reasonably well for the price here.

Soundstage

For soundstage and a general sense of spaciousness, I find the Deva does quite well. This is one area where it’s definitely better than the well-known Sennheiser HD6XX. That headphone’s biggest weakness is the distinct “three blob” issue where it has a very tight and towards you kind of sound that has gaps in the front left and front right. The Deva instead puts you slightly farther away from the stage, but still not as far as the Sundara. The Deva is also very open sounding, which makes sense for an open-back planar. 

Now I’m led to believe that the ‘open’ character of open-back headphones is often related more to the fact that sound leaks in and you can hear the world around you, but I still think this imparts additional advantages for the way sound waves are handled in general. You don’t have to create additional damping to deal with resonant waves bouncing off the back of the cup and back into the ear. And so maybe the ‘open character’ is simply correlated with the additional benefits that are gained from the fact that it’s an open-back headphone. In any case, the Deva has that advantage over closed-back wireless headphones.

And so while it’s not the largest soundstage at this price, the Deva is a solid middle ground that’s worth praising, because once again, the Deva is a wireless capable headphone, and compared to closed-back wireless headphones, I think this is the biggest step forward.

Imaging

For the imaging, I find the Deva’s placement of stage to be more in front of me than all around me, however occasionally I can hear certain elements that strongly token midrange frequencies as being somewhat pulled apart. This means that while there isn’t the HD6XX’s “three blob” issue - the stage is all reasonably filled in - it still occasionally comes across in a somewhat convoluted manner. This is perhaps the result of a slightly uneven midrange, or some additional resonance for tones and instruments that have a strong midrange focus. The effect can also sometimes create additional separation between vocals and the rest of the mix.

On that note, instrument separation is still very good with the Deva, and I generally find this to be one of the advantages of planar magnetic headphones. This means for any music that makes use of vocal harmonies, you’re able to isolate those individual vocal lines a bit more easily.

Timbre

Timbre is a bit of a funny category because there are two ways of looking at it. The first is to consider timbre as merely part of the frequency response, and this could potentially be improved with the use of EQ. So for example, if something has a congested type of sound, it can be improved by adding elevations or recessions to make it sound more normal. The other way to look at this is to consider timbre more like an analogy, similar to the way we think of different instruments playing tones of the same pitch. It might be something that’s captured by frequency response, but we’d have to look at it in such a granular way that any adjustments there would be unrealistic. And in this latter sense, the Deva’s timbral character comes across as a bit dry to me - almost reminiscent of the older HiFiMAN headphones (think again the HE-400i). 

I don’t think this is a huge issue, because this dry character doesn’t detract from the music the way that the dreaded balanced armature timbre might affect certain multi-BA IEMs. Instead, I think this is something that imparts a slightly more analytic edge to the overall sound.

Frequency Response & Tonality

A general note: measurements from the GRAS 43AG will be available for future reviews, but as of writing this it's still in the setup stages and hasn't been configured. I may add them here for the Deva once that's up and running.

The Deva’s tonality is generally agreeable and the overall frequency response doesn’t do all that much wrong. But that also doesn’t mean it’s without issues or as good as that of the Sundara. I should note that when the Sundara came out, it was priced at around $500. It's now come down to $350, making it the Deva's closest competition in terms of price. To some this might not seem fair, but for anyone looking to potentially spend around $350 on a headphone, the Sundara is one of the if not the strongest options - so it's worth looking at.

While the Deva’s bass is quite present, there’s a noticeable roll-off below 60hz. This means that you lose a bit of sub-bass definition as a result. I think when I first heard the Deva I thought it was more bass emphasized than it actually is, and that perception has more to do with only initially noticing it with mid and upper bass energy - which is slightly elevated. In any case, the bass roll-off on its own isn’t a huge issue because most musical information for bass tone exists above that anyway.

Moving up into the mids, things look mostly linear until you get to around 800hz, and then that’s where the unevenness I hear starts to come through. Again, this is a small issue and I don’t want to overstate it, but I do also think this is responsible for some of the concerns I mentioned in the earlier sections. When comparing against the Sundara, the mids just don’t sound as natural and resolving on the Deva. Granted, the Sundara is a bit more expensive and not wireless capable, so maybe this is an acceptable difference.

Where the Deva’s tonality differs most significantly from the typical HiFiMAN sound signature is in the upper mids and treble. Normally the HiFiMAN target tends to be fairly neutral with a slight dip around 2khz, and while the Deva has this, it sounds significantly more withdrawn above 3khz. This means that it’s not quite as revealing of the resonant harmonics for certain instrument tones and a bit more forgiving for worse recordings.

The Deva’s treble overall sits a bit lower than that of the Sundara also, and so it’s slightly more warm sounding, but then there’s also a slight peak in the consonant range anywhere between 7-9khz. And, like I mentioned earlier, this doesn’t exactly cause an over-emphasis to sibilant vocal sounds like ‘S’, ‘F’, and ‘T’, but it does cause a slight harshness to those tones - and when I say slight I mean very slight. It’s not noticeable on many recordings, but for some of my test tracks like from Patricia Barber for example, this starts to get noticeable.

The other key difference between the Deva and the Sundara is that the Deva also rolls off a bit in the upper treble by comparison. So anywhere above 11-12khz is a bit subdued, meaning that overall it just doesn’t sound as immediately resolving and pillowy as the Sundara does.

I think the nitpicks I’ve pointed out here may all add up to something when you compare it with the Sundara or Sennheiser HD6XX, but on the whole it’s easily still a good sounding headphone. When compared with other typical wireless headphones that exist in the consumer space, the Deva’s tonality is likely to be one of the better ones.

Comparisons

HiFiMAN Sundara ($350)

The Sundara is my favorite entry to mid level headphone, being excellent both in terms of tonality and technical performance for the price. It’s about as classically ‘neutral’ as it gets, with remarkable detail retrieval and image clarity. To my ear, the Deva doesn’t quite reach the same benchmark, sounding slightly less revealing for both tonality and technical ability. I think the real question with the Deva, however, is how close does it get to the Sundara. In my opinion, there’s still a bit of daylight between the two. This might prompt the question of how important or valuable the wireless functionality is. I can certainly see some listeners being comfortable with that trade off.

Audeze LCD-1 ($399)

The LCD-1 is a lightweight, portable, open-back (yes) planar magnetic headphone that has a totally different type of design from Audeze’s usual over-ear headphones. Audeze also provide their ‘Reveal+’ DSP presets for anyone wanting to get the most out of their headphones, and compared to the Deva, I find the LCD-1 to have better detail retrieval (in the treble in particular), along with a slightly more agreeable tonality. Without Reveal+, I think this becomes a more difficult comparison, since the LCD-1 has a more noticeable downshelf for the bass response. Still, it’s better extended in the treble, so this may just come down to preference. The Deva also has a more spacious presentation, as the LCD-1’s soundstage is closer to that of the HD6XX. Neither headphone has much ‘punch’.

Audeze Mobius ($399)

The Mobius is Audeze’s wireless headphone, but unlike the Deva the Mobius uses a closed-back design. It also differs in that the Bluetooth module is inside the cup for the Mobius, while it attaches to the outside of the Deva. I find that the Mobius has better detail retrieval for the mids than the Deva, but treble detail might be a bit closer. Using the ‘flat’ preset in Audeze’s HQ software gives it a fairly neutral response, however unlike the LCD-1, the Mobius does have a fairly strong bass shelf. The primary downside to the Mobius is that when you turn off its ‘3D’ simulation effect (something I prefer not to use), the headphone has a much more narrow and intimate soundstage, meaning that the Deva definitely wins there. I think the question here would have more to do with the use case, and perhaps the mobius gives the Deva the strongest competition. It’s a bit more expensive, but at the same time you do still get a wireless planar. I think when comparing these two, it will really come down to which sonic aspects you prefer.

Conclusion

This has been one of the more difficult headphones to evaluate. The fact that the HiFiMAN Deva is wireless capable puts it into the category of “wireless headphones”, which is often demarcated from audiophile and enthusiast communities who generally have different priorities. Despite a few quirks, the Deva is a generally agreeable sounding headphone - even by audiophile standards - and so, as a wireless headphone, the Deva is absolutely one of the better options out there. In many ways it sounds very similar to a wireless HE-400i. However, when considering the wired options around the Deva’s price, I think there are better alternatives like the Sundara or HD6XX. If anything, this just indicates that while big steps have been taken, and the Deva’s way of handling wireless will likely inspire even greater steps in the future, wireless headphones in practice still aren't quite on the same level as wired headphones just yet.

The other consideration for the Deva is that it’s an open-back headphone, meaning the use case for wireless functionality is also a bit different from typical wireless headphones. While there might be demand for this kind of product, I still think it fits within the narrow margins of the Venn diagram of an audiophile/consumer crossover - meaning it will best be enjoyed by those who actually do make use of its wireless functionality.

The bottom line for the HiFiMAN Deva, in my opinion, is the question of how much do you value the wireless functionality in your home. Personally, that’s not something I’ve fully seen the advantage of yet, but for those who really care about it, this may be a suitable solution.

Check out the video review below:

-Andrew Park (@resolve)

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Join the discussion about the HiFiMAN Deva at "The HEADPHONE Community".

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