This review is a comparison of three quad balanced armature in-ears: the Sony XBA-40, the Westone W4R and the Logitech UE 900. It is somewhat rambly and ranty and contains a lot of writing that is not even about these earphones at all. This is almost an essay that was provoked by writing this review. I hope you enjoy it.
THE ARMATURE ARMS RACE - or Micro-Drivers, YES WE CAN!
Clearly, Schoolhouse Rock was wrong. Four is a magic number. When I was a more junior member of Head-Fi, in-ears with four balanced armature were something of a techno-mystic concept - a Manhattan Project for a few brave companies to attempt. For a while, we thought the first to a quad would be JAYS with their X-Jays. Whatever happened to those anyway?
Today, we have several quad BA earphones on the market. Two of the earphones here are already second generation products - the Westone 4R and XBA-40. All of these earphones are brimming with armature-y goodness.
I am going to start this review off with some strong statements, some of which may be controversial, but this is something I've concluded when comparing these earphones.
None of these earphones are good value. I do not advise anyone purchase any of these earphones if you are looking for 'the best for x money', since you can get what I think is the same or a great level of technical ability for less money in a dynamic driver earphone. However, if very strong noise isolation and wearing comfort are absolute priorities for you alongside sound quality, these are good options.
I don't think that any of these earphones sound bad. But I do think with a quad balanced armature earphone you are paying for the complexity involved in making a quad balanced armature earphone, not necessarily in terms of perceivable benefits.
Multi balanced armature setups are complex and intricate attempts to overcome limitations observable with single BA units. Specifically, single BA units either have issues with high and low frequency extension (like the Westone UM1) or tend to distort when pushed to higher volumes (XBA-10, UE600).
This kind of over-engineering introduces it's own problems. Firstly, all these 4 BA earphones are physically quite large in the ear. Secondly, trying to achieve phase coherency (making sure all the frequencies from independent drivers arrive at the same time and do not interact with each other or cancel each other out) is its own challenge with multi armature setups.
JHAudio's Freqphase efforts and the low-frequency plate guide in the SE846 represent some really clever engineering, but they are also tacit admissions that trying to get many armatures to play nice is something that something they have not really done particularly well in the past.
The third issue is that the crossovers or other necessary compensations with these multi-armature setups is that they exhibit wild impedance swings that make them interact unpredictably with the output impedance of different amplifiers. Queue the endless array of mystical and expensive portable headphone amplifiers so that you can get everything 'just right'.
All these technical issues seem a bit moot when the last few generations of dynamic driver earphones more or less bypass these issues entirely. Dynamic drivers are by nature phase coherent up to their break up point because the diaphragm moves virtually as a single unit to reproduce the audio waveform. For a simple explanation of this idea, watch this video on B&W's site selling their diamond tweeters. http://www.bowers-wilkins.com/Discover/Discover/Technologies/Diamond%20Tweeters.html
The idea is universal: increased strength to weight ratio materials used in a driver diaphragm = higher rigidity driver = higher diaphragm break up point = better high frequency extension.
Perhaps at one point balanced armatures were able to reproduce more detail in the high frequency range on account of the lower mass of the moving element. Today with the kind of exotic high strength-to-weight materials being used in dynamic driver diaphragms - liquid crystal polymer diaphragms in the Sony EX1000, titanium metal deposition in the HIFIMAN RE-400 / RE-600 series, carbon nanotube vapour deposition in JVC's line of earphones, bio-cellulose drivers in the VSonic GR07 - this advantage seems nullified.
Micro-driver designs mean that even the last advantages of balanced armatures - namely, miniaturisation and high environmental noise isolation - are being ceded when models like the Sennheiser IE800, Etymotic MC3, Shure SE215 and Westone Alpha ADV are being released.
The last two earphones - the SE215 and ADV - are telling examples because they are multi-armature powerhouse companies dipping their toes in the dynamic driver kiddie pool while there are other companies like Sennheiser who have already learned to swim in the deep end. Meanwhile Sony, being the sensible and prescient company that it has always been, has decided to gatecrash the balanced armature party when people are already starting to leave.
What we now have as average consumers is access to publicly available measurements from various sources that lay the compromises of multi-armature setups bare. Measurements don't always tell the whole story - it is always going to be difficult to compress tonnes of psychoacoustic information into a bunch of squiggly lines, and then interpret these lines to mean anything at all. However, impulse response is an easy concept to understand. Think of it like the audio signal equivalent of a single hand clap. Impulse response is the response of the earphone when you the audio signal is just one impulse across the entire frequency range. A theoretically perfect impulse response should be one peak, followed by no decay - this is the driver moving once and then returning to the default position without oscillating (perfect piston). In the real world, the impulse response tells us something about the earphone - how sound initially decays after the initial impulse, whether or not there are resonance issues, and whether or not the drivers in a multi-way setup are arriving at the ear at the same time . Note that the impulse response tells us the overall energy without telling us what frequencies or drivers are arriving later, which is what a waterfall plot does.
With the three quad-balanced armature earphones in this comparison - W4R, UE900 and XBA-4 - you can tell from the impulse responses that these drivers are not firing in synchrony. You can tell because there are additional peaks following the first impulse peak that do not resemble natural decay from resonances.
The following graphs are from the data published over at Tyll Hertsen's great site Innerfidelity and Rin Cho's (udauda) audio blog http://rinchoi.blogspot.com.au/ Full credit and a tonne of kudos go to them for making this data available. I have reposted these graphs with some annotations for educational / commentary purposes and I believe this constitutes Fair Use, but if anyone has any objections I will take them down and leave the links.
Please be aware when comparing these graphs that Rin and Tyll use different testing equipment, different methodologies, and different time scales on their graphs. I am including these graphs to make a general comment about the time alignment of these drivers.
Comment: This looks awful. None of the drivers appear to be aligned at all.
Sony XBA-40 - The following is a graph of the XBA-4's impulse response, but let's assume that the XBA-40 has a similar impulse response since they sound so similar.
Comment: This impulse response actually looks okay except that you can tell one driver is firing right after the initial impulse (the second smaller peak to the right that isn't a decay curve). The third peak, under the graph line, also appears to be another driver's impulse.
You would expect that the XBA-40 would have the best impulse response given that all the XBA's drivers are wired in parallel with no crossover to introduce phase issues.
Comment: Again, these look awful.
Good single dynamic driver earphones like the Sony EX1000, Sony MDR-7550, VSonic GR07, HiFiMan RE-400 - all have impulse responses that have a strong initial impulse response peak followed by natural decay.
Sony MDR-7550: http://www.innerfidelity.com/images/SonyMDR7550.pdf
Vsonic GR07: http://www.innerfidelity.com/images/VSonicGR07.pdf
Comment: The RE-400's impulse response seems nearly theoretically perfect.
These graphs tell a story of sound waves from some of the four drivers arriving later than others. To my ears this seems to result in a slightly smeared transient response for all three earphones. Even if these different impulse peaks occur over what amounts to only miliseconds, hearing is a highly complex system and the brain uses differences in time alignment of sound waves to interpret spatial cues. For instance, an echo is a delayed signal which gives the brain spatial information about how big a room is.
If different frequencies arrive at different times, the brain will interpret the sound differently. Natural resonance from the earphone housing is a natural type of echo / decay that our brain can probably intrepret easily - but as to how the brain interprets different frequencies from the same earphone arriving at different times, I have no idea. But it can't be good in terms of natural reproduction or interpretation of sound.
What this also seems to me is that in the audio community, we get into a lot of needless arguments because we use hopelessly general terms like timbre and soundstage as catch-all phrases to describe hopelessly complex phenomenon.
You can have a 'wide' soundstage by tuning the drivers for more high frequencies above 4khz, since we get a lot of spatial information about room size from these high frequency echoes. We can have a wide soundstage by hearing decay in the driver housing - ie: the earphone is literally adding extra echoes that were not present in the original recording. Perversely, we can imagine a situation where we can have a 'closed in' soundstage because an earphone simply doesn't really add any extra echoes or reverb at all - something like the RE-400. Remember that recording artists use the same headphones / equipment as we do. If they hear reverb from their headphones, they won't add it to the original signal.
Same as with timbre. We can have what sounds like natural timbre because the housing resonances add what is essentially distortion in the form of decay. We can get a sense of a 'live space' to a studio recording by adding timbre this way with earphones. I think this is one of the Sony EX1000's most admired qualities.
If we have an earphone that not only adds more decay, but literally has the sound at different frequencies arriving at different times, what do we get? I think the reason why we think many of these multi BA earphones have soundstages that we describe as 'euphonic' or 'holographic' is because the brain is getting confused by audio cues arriving a few ms off.
Some people like all the above effects. Some people don't. Some people think particular kinds of decay or distortion sound natural, some people don't.
I'm trapped, like everyone else, by the language we have on hand. Since we can't talk in graphs, lets at least be aware of the fallibility of the language.
But back to the earphones.
To my ears, all these dynamic driver earphones generally sound cleaner. more natural and more coherent. This is significant considering that these kinds of earphones generally cost less, or in the case of the Sony EX1000, cost the same but are actually milled out of materials (magnesium alloy) that are durable, and well, premium.
The writing is on the wall. Bar Sony and some cottage industry 'audiophile' boutiques we are seeing the industry start to move towards micro-drivers. The earphones in this comparison may be some of the last of the flagship BA earphones. I think that this is a good thing, because far from being a fancy 'audiophile' solution, multi-armature setups are the manufacturers buying OEM drivers from Knowles or Sonion and putting them in a variety of colourful plastic shells. It all seems a bit clumsy, like selling a digital camera because the megapixels, are like, more and stuff. You are paying for the added complexity when the benefits are hard to place.
I also find it difficult to accept paying these prices for high end balanced armature earphones when they are made out of plastic. This is a bit sad considering that other companies are making their earphones out of metals and ceramics - things that fancy expensive trinkets should rightfully be made of. Manufacturers will continue crafting several hundred dollar earphones made of plastic as long as people keep buying them.
I'm not suggesting that manufactures use non-resonant materials when it makes no audible difference (arguable), but consider this: the HiFiMan RE-400 is made out of aluminium and the FXD80 is made out of stainless steel. They are both good earphones under $100. Westone and Sony have demonstrated with the Alpha ADV and EX1000 that it is possible to make an earphone milled out of a single piece of Magensium alloy.
The SE846, with its 'stainless-steel' nozzle, actually has a body made out of plastic and a giant inner tube / filter in the nozzle made of plastic. It costs $1000. The UE900 in this comparison, besides its most glaring quality control issue, also has reportedly fallen apart in the hands of users because the plastic come apart. The Westone W4R is made of nice soft touch plastic, sure - but it's still plastic. The XBA-40 barely gets a pass because it is cheaper than these other quad balanced armatures - but even Shure has demonstrated with the SE215 that you can design a plastic IEM with detachable cables and a negative profile fit and have it cost under $100.
How is any of this acceptable? This is like Lamborgini releasing a car made out of plastic when Lexus is making cheaper high performance cars out of carbon fibre and aluminium. It isn't right. It clearly doesn't cost a great deal more to use non-resonant materials, it shouldn't cost a premium price to do it.
All this 'Big Dynamic' lobbying aside, these are still interesting earphones to compare. I do not think any of these earphones sound bad, they just strike me as an overpriced solution to an avoidable problem. This includes the XBA-40, which I have not thought particularly highly of since discovering the SE215 LTD. I am especially disturbed by the quality control issues of the UE900 which I mention below.
I do earphone reviews on Youtube, and if you want a closer look or a short summary of some of these earphones, check these out. The videos go through the comfort and design of these earphones as well as touch on the sound in general terms, but since I made these videos at different times, the sound comparisons below will probably be more helpful and accurate.
All three of these earphones do not sound neutral or balanced, with the XBA-40 sounding thick and bassy, the W4R sounding warm and mellow and the UE900 sounding V-shaped and somewhat hollow. All three have very strongly euphonic and holographic sound stages, and I am starting to think that these soundstages sound oddly holographic precisely because the drivers are not time aligned and are displacing instrument positioning in strange ways. Still, all three sound a treat for electronic or synthetic music where we lack real world references.
I have already written quite a bit about the XBA-40 in my comparison review here. The Sony XBA-40 is by far the cheapest quad balanced armature in this comparison. It is also the most rudimentary in design, with no detachable cables and a non-negative (positive?) profile design that sticks out of the ears and is difficult to wear cable up. Because of this, it is susceptible to wind noise and cable noise and cannot be worn lying on your side. Luckily it is lightweight and otherwise built quite nicely. It seems to offer the least noise isolation out of these 3 contenders.
In terms of sound, the XBA-40 does not have the same metallic shimmer that its predecessor the XBA-4 did. The XBA-40 is the most congested sounding of all of these earphones because of its strong bass emphasis. Strangely enough, it also sounds to me to have the most natural timbre and to be the least 'BA' sounding of all three of these earphones on account of its natural sounding decay / resonances.
Bass / Synths / Drums
The XBA-40 has the strongest sub-bass / bass emphasis of all these 3 earphones. It sounds tremendously visceral with a strong sense of decay and rumble. It reaches deeper than the W4R (which has a bit of noticeable roll-off in the sub-bass) but is not whistle clean and fast like the UE900's similarly deep bass. If bass is a priority for you, I would look either at the XBA-40 or the UE900. Personally I prefer the XBA-40's bass because it sounds more natural to my ears - the UE900 sounds oddly tasteless.
Mids / Vocals
The XBA-40 has mellow, smooth vocal reproduction. It is exceedingly pleasant and inoffensive to listen to, with an intimate and throaty, mid-bassy sound that emphasises male vocals. For reference, while the XBA-40 sounds the lushest of all these earphones it does not sound as lush as something like the SE215.
Treble / Strings / Cymbals
Treble on the XBA-40 is definitely the least emphasised aspect. There is no real treble peak, but there is a broader residual treble shimmer that lends everything just a tiny bit of energy and sparkle. Overall though, the lack of treble means that the XBA-40 sounds fairly sleepy. If you are sensitive to sibilance, the XBA-40 is a good choice.
Because of the treble roll off and the rich mids and bass, the XBA-40 has the most immediately intimate sounding soundstage. Articulation within this soundstage is on par with the other 2 quads.
Despite being the cheapest quad BA in this comparison, the XBA-40 holds up surprisingly well with a smooth, easy sound. While it is not a bargain priced model, it seems particularly better value than the other two models in this comparison unless detachable cables and over-ear fit are extremely important to you.
I borrowed the Westone W4R from a friend and fellow headier Kookoo. The W4R is the most ergonomic earphone in this comparison, with a negative profile design that nestles comfortably in the ear, short earhooks for simple over-ear wear and simple detachable cable connections. The W4R is nicely built but compared to the new Westone ADV Alpha with its unibody magnesium build at a lower price, the W4R still comes off looking less special.
The Westone W4R is the middleman in this comparison, with the most balanced sound signature of the three. It is still warmer and lusher than neutral sounding IEMs like the GR07, 7550 or RE-400.
Bass / Synths / Drums
Bass on the W4R is noticeably humped in the mid-bass compared to the linear rise of the UE900 and the rumbly sub-bass of the XBA-40. This is what probably helps the W4R sound more delicate than the XBA-40 and UE900. This is not to say the W4R is bass deficient - mid-bass instruments are carried off with aplomb, but if sub 100hz wub wub is your thing, you may want to look past the W4R.
Mids / Vocals
Vocals on the W4R sound a bit more distant compared to the lush and intimate vocals of the XBA-40, but they still have a wonderful sense of body and warmth. Vocals on the W4R have a slightly dry tone to them, with a bit of grain for flavour.
Treble / Strings / Cymbals
The W4R has a slightly grainy, peaky tone to the treble. To my ears, it still sounds smooth, though the treble adds texture. Just like the XBA-40, the treble does not appear to extend particularly far.
The W4R has a slightly wider soundstage than the XBA-40, but it is again fairly intimate and closed in sounding. Articulation within the soundstage is again excellent.
The W4R is my pick out of the three earphones in terms of sound, but it has a very high price that does not seem to translate to particularly better technical ability. That said, it is designed well, comfortable, and certainly sounds good - as a complete package this is worth something.
LOGITECH UE 900
Simply put, the UE 900, or at least the batches leading up to my serial no. 1245x have a quality control issue. The UE 900 thread has a number of people (including myself) complaining about the sound cutting out on the earphones due to some issue with the detachable cables. Apparently the issue is some residue that either the connectors comes out of the factory with, or develop over time.
Although Logitech is apparently responsive and making good on the 2 year warranty by providing replacement units, there are numerous Amazon reviews from happy users that have their UE 900's fail after a few months. It may not be a huge problem, but it is unacceptable for such an expensive earphone. If this is an oxidisation issue (which it appears to be given that people have reported success following cleaning the contacts with contact cleaner) it would be easily anticipated. I forgot all my high school chemistry but even I know this is why we use gold plated contacts etc. Logitech is selling this earphone for $300-$400 and then expecting customers to do a run-around because they cost cut on the connectors.
Another point of failure seems to be that the UE 900 will simply fall apart at the seams when changing cables, or the black faceplate will simply rub away.
This is all extremely troubling and again, I find it really hard to recommend an earphone with these sorts of issues no matter how it sounds. 2 year warranty or not, it isn't worth the hassle.
As for the rest of the build, I am not so sure about it. For one thing, the UE900 looks like a pair of little jelly cups, and has all kinds of glossy and chintzy chrome accents that feel cheap. It doesn't feel badly made, just a little excessive and overbuilt. The swivelling detachable cables allow for greater fit flexibility but are a little fussy to take in and out. The UE900 offers very good noise isolation and comfort, though the W4R is more comfortable, isolating and unobtrusive. I would laud the detachable cables and the accessory selection of the UE900 (especially the really super nice carrying case) but the Shure SE215 LTD has almost all these features at a fraction of the price.
The UE 900 sounds the cleanest out of all the earphones in this comparison, with stellar technical ability. However, if you couldn't tell by the little clues I've been leaving throughout, there was something about the signature of the UE 900 I didn't like - after an initial positive feeling I just started to find the sound a little tasteless and unengaging - most likely because of a noticeable scoop in the mids.
Bass / Drums
The UE900 has some amazingly fun, deep and fast bass. It is whistle clean but seems to lack the kind of decay that would make it sound natural for taiko drums or cellos. However, it does nicely for synths and machine drums.
Mids / Vocals
As I stated, the mids in the UE900 just leave very little impression. They are there, they are very clean and clear, but compared to the two other earphones in this comparison they just feel hollow. However, if you are a fan of V-shaped signatures this may be a good thing.
Treble / Strings / Cymbals
The treble on the UE900 is quite impressive, with a great deal of detail, liveliness and clarity without being sibilant. However, it is still relatively rolled off compared to neutral IEMs. Again, to return to the reference GR07, treble on the UE900 still does not sound as clean or defined.
I felt like the UE900 had an interesting soundstage. On the one hand, it sounded more forward and in your face compared to the other two earphones. At the same time it felt less intimate because it didn't have as much sense of 'stuffiness' in the sound because of a lack of mid-bass warmth. It sounded good with electronica but not so great with live recordings.
The UE900 is a nice sounding earphone, but not my preferred signature. I got my UE900 for $299 AUD in a sale, but the price still seems fairly high to me for an earphone that does not seem to have a particularly premium feeling build. The accessory selection is very impressive. If I could buy that magical carrying case separately I would.
The build quality issues are a tremendous turn-off, but I will update this review if anything comes up.
CONCLUSION (FOR NOW)
I hope this has been an interesting read, though clearly there has been a $1000 plastic elephant in the room this whole time. While I would love to have a listen to the Shure SE846, sadly it may be some time before that is even possible for my budget. One thing I do not expect though is for there to be 5 BA universal IEMs. I do have a strong feeling that the industry is now moving towards dynamic and micro-drivers, and I think this is a trend that the community should embrace.
I think that if you can buy a RE-400, GR07 and FXD80 combined for around the same price as a W4R or UE900 tells me that there is something very wrong with the value equation of these multi balanced armature setups.
This review was written with a number of aims in mind. The most obvious one would be to write a review for people who are interested in comparing these giants. My second aim though is to make this point: more is not better. More money is not better. More drivers is not better. Many people will come to this review with the intention of only buying the most expensive thing in one pricing tier. I think this is an incredible shame because it leaves them blind to cheaper options that, to my ears, are not subjectively worse.
We see this happen a lot - the assumption is that a $100 earphone can't possibly sound as good as a $400 earphone - and even if it does we can't bring ourselves to think that way. I myself have trouble believing my own ears sometimes when I listen to some cheap dynamic drivers. Surely this can't be right? Don't the manufacturers set prices based on audio quality? Isn't there some kind of relationship between audio quality, material cost, and price?
The relationship seems tenuous at the very best. The manufacturers set their prices based on what people will pay. In many ways the big names like Shure and Westone only have to compete with themselves - each new earphone can get more and more expensive because it stands on the shoulders of the previous model and consumers think more is better. They are not going to lower the prices on balanced armature earphones - technology that they have undoubtedly spent millions and millions of dollars and man-hours of engineering on - simply because there are upstart chinese OEM companies on the horizon doing better things for less money.
These large companies are not in the position where they can just abandon all their existing technologies and start all over again with different technologies, because their companies have been built up to pay employees a certain salary to make products with certain average selling prices and operating margins. These companies will not simply throw up their hands and reprice their entire lineup even if they wanted to. Which they don't, because luckily audio is such a subjective hobby that different technologies and innovations are not immediately recognised as superior. Keep in mind that massive transitions tend to involve a lot of pain for people.
Meanwhile, the floor is open for upstars like Vsonic and HiFiMan to undercut these entrenched manufacturers. Because really, they have no history of pricing, no roadmaps, they don't have vested interests enshrined into monolithic structures of middle management, shareholders etc etc. Really, the small companies have comparatively little to lose. Which is why HIFiMan can undercut their entire earphone line and release something like the $99 RE-400 without breaking a sweat.
But this is Head-Fi, and we have references. Again, I reiterate - I don't really think any of these earphones is great value for money. But like the hobby itself, the concept of value for money is subjective to the point of being meaningless after a certain point. There are people who hold the position that spending anything more than a few bucks on earphones is ludicrous because they break, get lost, or my favourite - people claim that they cannot hear the difference in sound. Which might be true. The ancient Greeks apparently did not see the colour blue.
We are still waiting for that holy grail of earphones - the one that has detachable cables, that is made out of unobtanium, that has a diamond / carbon nanotube / beryllium micro driver, that has a negative profile design with no cable noise - and that doesn't cost $1000.
Some day Head Fi. Some day.
Edited by a_recording - 8/28/13 at 10:30pm