DISCLAIMER
This review is based on a loaner unit I got from RHA from their Europe Head-Fi tour. I got the opportunity to audition their IEM for around a week before sending it to the next one in line. Thank you RHA for the opportunity! I have no prior experience of any RHA products, although I’ve almost bought the T20 on a few occasions. As for RHA (or any audio company), I have no financial or personal ties to them and actually did not even keep contact with them much during the time I had these in order to stay as neutral as possible. In addition I purposefully did not read any reviews before writing this up (just saw a few impressions posts on the main CL2 thread, but even there I’ve maybe spent 20 minutes tops). There is no financial incentive to write a positive review. Communication with RHA over the package shipping was a pleasure, they were always quick to reply and professional. All listening was done either at home wired via 3.5mm to RME ADI-2 DAC via its IEM specific port or portable with the included Bluetooth cable.
The official RHA CL2 Planar website is: https://www.rha-audio.com/ca/products/headphones/cl2-planar (I will be referring to the frequency response chart posted there in this review, although I just noticed there's a more accurate one posted in one of the other reviews)
Although I am using the word review throughout this article, please keep in mind that this is all written based on a week of listening and I would have preferred to listen to these more extensively, but it’s a tour with a fixed schedule and I wouldn't have wanted to delay it anyway. What I am trying to say is this: consider these extended impressions instead of a traditional full review (which in my experience needs a month or so of steady listening to form a good solid opinion).
CONTEXT
Since reviews without any context are (if you ask me) often at the minimum quite confusing and at the worst pretty useless, here is a list of some of the IEMs I’ve owned and eventually sold on in the past: Sennheiser IE 80, IE 800, IE 800 S; Shure SE 530, SE 846; Ultimate Ears UE 900; Fischer Amps FA4E-XB, Rhapsody; Jays Q-Jays (current version); EarSonics SM64; HIFIMAN RE-600S. Comparisons are thus from memory, but I'm pretty confident this does not effect things that much as many of those IEMs are ones I used for a very long time.
Why are all these now gone? I intend on going wireless only when it comes to IEMs. For me portable audio needs to be truly portable and nothing is more portable than wireless. Home setups are a different matter entirely, but on the go I want something that gets out of the way and disappears. This is actually the main reason I applied for this tour: the CL2 seemed to me to be one of the ground breakers when it comes to finally getting high end sound quality in a wireless setup. I might be missing some products, but from this point of view I see it its main competition being the AKG N5005 and Beyerdynamic Xelento which both come “wireless ready”. Both are however more expensive than the CL2. Unfortunately I haven't heard either, so I can't make any comparisons there.
As for my tonality preference, out of everything I've heard I consider the Sennheiser HD 600/650 and the Focal Clear to be the best tuned headphone audio products thus far. In the IEM world the Sennheiser IE 800 S takes the crown. From this you may guess that I value a smooth frequency response with mids and treble that do not have any major spikes. Ideally a headphone needs to be able to handle all kinds of music. Being genre-specific is generally a bad sign: the original Sennheiser HD 800 likely being the most famous example.
Now I know many audiophiles are at the very least, well, let’s say conservative when it comes to accepting wireless audio. After all lossless is considered the standard and yes, there is a small difference between modern lossless and lossy files. The difference however in my experience is definitely not as big as is often claimed and and the very least it’s very difficult to hear on anything most mainstream music. Classical, vocals and other genres with minimal compression are a different topic entirely though, in those the difference is much easier to hear. In any case the AAC (and others) codec of today is not the same as five years ago and huge advances have been made in both cods and Bluetooth technology. In other words the sound quality gap between wireless and wired is getting smaller day by day.
The CL2 however strikes the ideal balance: it caters to the traditional audiophiles by offering a wired option (two actually, one cable is for balanced use which many no doubt will appreciate) along with the wireless, so everyone can make up their own mind which one they want to use. This is just my guess, but I’m betting a lot of people will start using these wired and eventually slowly move into using them almost exclusively wireless...
FIRST IMPRESSIONS
I always knew RHA had build quality locked down. It’s pretty obvious: just look at the build materials, online videos and so on. In other words I expected to be impressed with the unboxing and surely enough I wasn’t disappointed. It screams high end and quite frankly makes a mockery out of many competitors. The way the box opens has a bit of an Apple style vibe with the IEMs being in the middle with their cables disconnected. Let’s check out the accessories first: there’s the wireless cable, two wired cables (one copper 3.5mm and one silver-planted 2.5mm balanced), a carrying pouch, an airline adapter and a selection of tips (more specifically a mix of double-flange, silicon and Comply ones in different sizes) on a metal tip holder that works surprisingly well.


The first surprise however were the IEMs themselves. They are much, much smaller than I thought they would be judging by the pictures. The form is quite close to the classic Shure/Westone (+ Earsonics SM64) style, which is actually my favorite shell style. It’s a classic with a good track record. You can already guess how well the shells fit my ears (and I’m pretty sure they will fit most people really well; better than many other designs), but what isn’t apparent in the pictures is how nice these feel. The RHA website mentions that these are built from ceramics and these do indeed have a similar feel as the Sennheiser IE 800, although the CL2 feels more solid, weightier in a positive way and somehow tougher. This is quite a surprise considering the CL2 weighs 9 grams vs. IE 800’s 8 grams without a cable. These are basically built like a tank and feel more or less indestructible, although I have no idea how well these can take hard hits against concrete and so on (with IEMs this expensive that shouldn’t really be happening though). My guess is that the ceramics layer is thicker than on the IE 800 series since they also feel quite cold before warming up. Or it could just be because the material is different: the ceramics they are using here is zirconium. Ceramics in general is probably the ideal material for IEMs since it is extremely stiff and durable, the downside being that it’s expensive to work with and is thus only seen in higher end products.
As for the design, the CL2 looks high end yet minimalistic. It won’t gather any unwanted attention on the subway like perhaps the Beyerdynamic Xelento would. Now aesthetics is obviously a very subjective topic, but personally I’m a big fan of this approach. They don’t draw attention to themselves, look good with any clothing style and aren’t really that divisive compared to something more brash looking.


As for the cables, the wired ones I feel are bound to divide opinion. They are quite thick, heavy and the colors are a far cry from the minimalistic and understated look of the IEM itself. Some will love them, others will feel they are too thick and difficult to handle (and may not be a fan of the aesthetics). I personally fall into the latter group, although I must admit the silver cable to me looks much better than the copper one. Hopefully RHA will sell the silver one in a single ended configuration someday?
The wireless one is a different matter entirely: it follows the same minimalistic design philosophy as the IEM itself and well, it just disappears. The design is beautiful. The plastic/rubber mix feels nice to touch, it doesn't feel cheap in any way and is just something that looks like it belongs with the CL2. It initially feels a bit heavy when you pick it up, but when actually wearing it the weight distribution is so good that it basically disappears. The wires coming from the battery section are also just the right length and do not to hang out in an annoying way. It's also worth emphasizing that it has a USB-C port for charging. Finally... Audio for whatever reason has been very slow to adopt USB-C despite its obvious advantages. The Chord Hugo 2 for example still uses Micro-USB, which if you ask me diminishes the value of the product somewhat. Micro-USB has a habit of breaking down and is just very flimsy feeling in general. You’ll find none of that with USB-C plus the cable orientation doesn’t matter anymore. The cable charges quickly and I didn’t have a problem with running out of power during the day. Never experienced any audio cutouts either and the pairing process with an iPhone X was a breeze. I unfortunately forgot to measure how long the cable charge lasts, but hopefully someone else from the tour can do that since it’s probably something a lot of people want to know.

These IEMs use MMCX connectors. I’ll be honest with you: I’m not a fan. I’ve had a UE 900 and Shure SE 215 that both used this connector and developed audio cutouts to the point where I found using them very annoying. However on the other hand I had the Shure SE 846 for quite a long time and they never had a single issue despite using the same connector. I’m hoping the CL2 will be similar, but in addition to potential cutout issues my main grievance with this type of connector is the basic swiveling function they have. In my experience it doesn’t improve finding a good fit, it makes it more difficult as you have to adjust them more often. With a classic 2-pin connector like on the EarSonics models you just bend the memory wire to suit your ears and forget about it: since it won’t swivel they will always feel the same when you put them on. This is however a theme that divides opinion a lot, there are also a lot of fans of this connector. That being said, however one feels about MMCX in general, fact is that these have more or less become a standard in the industry so from that point of view I understand RHA going this way. For me it’s definitely a minus though; even if they never develop cutout issues, I just don’t find MMCX cables as comfortable/solid feeling (with over ears IEMs) compared to the traditional 2-pin connector that’s used in many custom made IEMs and also some universals like in the EarSonics ones.
As for the included tips, well, with universals it’s always down to luck. When I saw the tip selection I was pretty sure I wouldn’t encounter any issues, but to my surprise I could not get a decent seal with any of the double-flange or silicon tips. Only the Comply ones seemed to seal, and those aren’t tips that I would normally use just because they are slow to put on, wear out fast and because of that just aren’t all that suitable for portable use if you ask me. I'm not sure, but the nozzle looks quite similar to the classic Logitech style on UE 900 so I was left wondering if perhaps the UE 900 tips would fit these well. Unfortunately I don’t have them anymore so I couldn’t test. Don’t get me wrong, the Comply foams feel very comfortable once they settle in, but for me IEMs need to be used with silicon tips so you can quickly take them out and put them back in without having to replace tips that often. Hopefully RHA will expand the silicon tips selection in the future, although I have to say it’s not currently bad at all (instead it's better than on many competitors like the IE 800 series); I was just unlucky.
Unfortunately the CL2 does not feature RHA’s tuning filters. This has two downsides: first of all if the stock tuning isn’t to your liking you are out of luck (unless you EQ them, but EQ is not something I am willing to do with portables unless there's a product specific app that uploads the choices to the IEM itself so they work universally), but also there is now no 100% safe ear wax filter (except on the Comply tips which have one, but that’s another matter) on the IEM itself. On an IEM this expensive I would have prefered to see some system that is 100% safe. There is however a metal spiral part that likely helps keep ear wax away from the grid section.


Once I finally pressed play I was instantly impressed: bass was very deep and punchy as expected, but it never overshadowed the mids. Resolution seemed high and soundstage was far larger than I expected from a closed design planar driver. Even the treble extension – traditionally a weak spot with planar drivers – was very good. However as I listened to different songs I noticed there was kind of a rough feel to the sound as if the drivers hadn’t really settled in yet. So I left them to burn in and continued later. It turned out this was a smart move: these were apparently straight from the factory without much (or any) burn in and they did indeed settle down a lot. So a note to all future listeners: burn these in for at least 24 hours before starting to listen. Oh and for the record I’m not even a big believer in burn in, but planar drivers seem to be an exception (I’ve had similar experiences with full size planar headphones; balanced armature IEMs on the other hand never seem to need any burn).
That being said, first impressions in audio are notoriously unreliable. If something really wows you the first time you listen to them it may even be a bad sign: the HD 800 is a good example. It’s probably the best case study of a product that creates an almost unbelievably good first impression when listened to which carefully chosen music, but then in the long run many end up selling due to the treble spikes (or lack of bass). In my experience high end audio products typically have at least some major flaws, it’s more or less to be expected. Finding an all rounder with a smooth frequency response is extremely rare and that's the ideal to aim for. That’s why the Sennheiser HD 600/HD650 series are still so popular even after all these years: they may sound unremarkable at first, but they have no serious flaws and offer some of the smoothest frequency responses on the market. The IE 800 / IE 800 S are also interesting in this regard: the original IE 800 has too much bass and treble for a lot of people making it good for outdoors use in noisy areas, but a bad for indoors use. Or a genre specialist for pop/hiphop/electronica, depends on who you ask… The IE 800 S took a different direction and toned down both the treble and bass leaving a very smooth frequency response, but on the other hand some will feel it lacks the “fun” factor the original had. But let’s finally get to the more in depth sound quality parts of this review...
RESOLUTION AND SOUNDSTAGE
Planar drivers aren’t really generally known for being the most resolving ones. They have a lot of other virtues like class leading bass performance, but raw resolution in my experience just isn’t one of them. That’s why I was very surprised to notice that these are actually very resolving IEMs. Not on the same level as the IE 800 S for example, but clearly superior to your average 300-400 euro price range IEMs. Now I haven’t heard that many planar headphones, but I would say these are more resolving than the Audeze LCD-2 Classics (which I’ve owned) or likely even the HIFIMAN HE-1000 I’ve auditioned. That being said, I’m not completely sure if this subjective feeling of a high resolution is entirely down to “real resolution” or if it is partly enhanced by the boosted upper midrange. My guess is that the truth is somewhere in the middle: that this is an exceptionally resolving planar driver, but the tonality is also designed to provide some added “fake” sense of detail. More on that in the midrange section though.
The thing I expected the least out of these was hearing a wide soundstage. I know many disagree, but I’ve never heard a planar that didn’t sound at least somewhat claustrophobic and closed in. There’s none of that here, which is almost a miracle considering these are not only a planar design, but in addition to that a closed shell design. To put things short: these have a wide and tall soundstage that often makes you forget that you are listening to IEMs. Not many IEMs pull this off, so this is definitely one of the high points here. The only minus when it comes to the soundstage is that the depth is not on the same level as the rest (for example the IE 800 series is clearly superior in this regard). Instrument separation is also very good: above the typical cheaper IEMs, but not best of class. Out of everything I’ve heard that award still goes to the IE 800 series. All in all considering the technology being used here and the closed design the soundstage performance is exceptionally good.
BASS
So far so good… Now this part you probably already guess what I’m about to write. This is a planar driver after all and bass is simply what this technology does the best. This is where planar drivers excel and one of the main reasons many find it very difficult to go back to dynamic or balanced armature drivers after getting used to planar bass performance. That being said, there were also a couple of surprises here. Let’s start with what you probably do expect: yes, the bass is ultra clean, tight and goes very deep. However it also fast: subjectively there isn’t a lot of extra decay, so instead it sounds tight, tuneful and never bloated.
The surprising part here that there is no artificial bass quantity boost, which is usually common with planar drivers because it's a nice way to show of the technology. You won’t find that here. These aren’t bass cannons at all and instead go for neutrality. This doesn’t mean the bass quantity is lacking per se, but these do not have the added bass boost some IEMs have that lead to a “fun” sound tonality that often suits genres like hip-hip/electronica well. That being said while I didn't try EQ with these, planar drivers typically respond well to EQ so on a home rig at least it should be easy to add a couple of dB of sub bass for that extra kick. The official frequency response chart (although very smoothed over as official ones always are) seems to support impression. All in all these probably have the cleanest, fastest and deepest bass I’ve ever heard out of an IEM. Personally I would have preferred to have a bit more sub bass boost though, but unfortunately that option is only there with EQ. The inclusion of tonality adjusting filters would have helped here.
MIDS
This is where things for me got problematic. Now I’m a fan of smooth, linear midrange that does not have any major dips or spikes. Our ears are also the most sensitive in this area too. For me this part in the frequency response makes or breaks an IEM. In my experience IEMs that stray too much from linear here can often sound shouty, fatiguing and the realism of the vocals suffers as well. I’ll start with the good news: due to the neutral tuning the bass never, ever intrudes on the midrange. It doesn’t matter how much bass is in the mix (or how deep it goes), midrange will always stay clear of bass influence. In fact it’s not just a matter of not intruding on it, but parts of the midrange are actually boosted on this IEM to bring vocals forward. I’m again referring to the official frequency response chart on the RHA website: notice the rise beginning from the midrange (500Hz to 2kHz) and then the clear spikes in the upper midrange (2kHz to 4kHz). This spike in the upper midrange is often used in headphones and IEMs among other things to boost the sense of detail (however one can argue that it’s fake in a way), but nothing comes free: it can also make sibilance worse or just sound unpleasantly shouty/sharp on certain material. Unfortunately the midrange tuning style in the CL2 is not something I generally like and I have to say that in many aspects this proved to be a deal breaker for me. Sibilance wasn’t the issue, but the CL2 had the latter issue on many songs. On a home rig I would definitely want to EQ this down.
As it generally is with headphones with similar midrange tonality, it really depends on what you are listening to: in many albums there are no problems and the tonality may even sound subjectively better than a more neutral approach, but on many albums I found the sound too fatiguing/piercing after a while. Overall this breaks the CL2 as an all rounder for me. I would personally have preferred a more linear midrange (no upper midrange spike) at the expense of less perceived detail. Generally speaking this kind of tuning (at least to my ears) is more of a problem with mainstream genres than audiophile ones though, so it partly depends on what kind of music you listen to the most. Note however that I am probably a lot more sensitive when it comes to midrange: for example I found the Shure SE 846 midrange to be too shouty/edgy as well (not as much, but to an annoying degree). All this being said, there are of course also a lot of people who prefer boosted upper mids, so it all comes down to personal preference.
The resolution on the other hand continued to impress: vocals were often very realistic and when an album is mastered in a way where the upper midrange spike doesn’t offend, the results are often stunning. However due to the dB level difference between lower and higher mids some vocals can sound a bit off/muddled depending on where they hit on the frequency response. This is another downside to the chosen midrange frequency response tuning.
TREBLE
Planar drivers can’t do treble well. That’s at least the stereotype and to my best knowledge getting treble right is one of the main challenges when working with a planar driver (vs. getting bass right on a dynamic). Well, this one defies the odds here and is definitely not your typical Audeze LCD-2 Classic or even the Shure SE 846 (where the treble seems to fall off a cliff pretty fast). Now the treble here isn’t the smoothest or most detailed out there compared to the highest level of competition (IE 800 S for example is on different level), but it is very impressive for a planar driver and a critical part in creating that awesome soundstage. The CL2 treble is nicely extended and that's something I wasn’t expecting to hear at all. The is a slight roughness in the treble that isn’t apparent in high end balanced armatures or dynamic driver IEMs, but it wasn’t something that annoyed me much. Due to the slight roughness the resolution here didn’t sound as it was quite on the same level as in the midrange and bass, but the difference wasn’t drastic enough to make it stick out too much.
CONCLUSION
This one is tough… From the moment I opened the box I wanted to love them. They do so many things right: a superb wireless cable design, industry leading build quality and comfort, they're priced fairly and of course the quality impresses in many ways. On the downside however it goes with the MMCX connectors and the only tips that worked for me were the Comply ones (just bad luck; I doubt many will have this problem). It’s main issue however to me is the midrange tuning that artificially boosts the sense of detail, makes certain material sound shouty/fatiguing and for me that simply breaks it as an all rounder. The treble is also slightly problematic, but that is something I would gladly take in return for getting freed from the traditional claustrophobic planar driver sound.
Would I recommend it? Yes if you have a preference towards this kind of tuning, are ok with MMCX connectors and know from past RHA products that the tips fit you well. For others I would say it’s an IEM that you need to audition before making a decision or buy from a place that accepts returns. Then again that’s what I would say of more or less every expensive universal IEM out there. To sum things up: add 1+ star if the midrange tonality is to your liking and you have nothing against the MMCX connector type. Personally however I believe IEMs need to be all rounders and I place a high value on frequency response smoothness so for me this is unfortunately (despite all its virtues) a pass. I just wish RHA would have kept their sound tuning filters technology or perhaps supported an app that can upload EQ settings to the bluetooth cable. That could have solved the most pressing issues for me (except for the Comply one, but fit with universals is down to luck).
This review is based on a loaner unit I got from RHA from their Europe Head-Fi tour. I got the opportunity to audition their IEM for around a week before sending it to the next one in line. Thank you RHA for the opportunity! I have no prior experience of any RHA products, although I’ve almost bought the T20 on a few occasions. As for RHA (or any audio company), I have no financial or personal ties to them and actually did not even keep contact with them much during the time I had these in order to stay as neutral as possible. In addition I purposefully did not read any reviews before writing this up (just saw a few impressions posts on the main CL2 thread, but even there I’ve maybe spent 20 minutes tops). There is no financial incentive to write a positive review. Communication with RHA over the package shipping was a pleasure, they were always quick to reply and professional. All listening was done either at home wired via 3.5mm to RME ADI-2 DAC via its IEM specific port or portable with the included Bluetooth cable.
The official RHA CL2 Planar website is: https://www.rha-audio.com/ca/products/headphones/cl2-planar (I will be referring to the frequency response chart posted there in this review, although I just noticed there's a more accurate one posted in one of the other reviews)
Although I am using the word review throughout this article, please keep in mind that this is all written based on a week of listening and I would have preferred to listen to these more extensively, but it’s a tour with a fixed schedule and I wouldn't have wanted to delay it anyway. What I am trying to say is this: consider these extended impressions instead of a traditional full review (which in my experience needs a month or so of steady listening to form a good solid opinion).


CONTEXT
Since reviews without any context are (if you ask me) often at the minimum quite confusing and at the worst pretty useless, here is a list of some of the IEMs I’ve owned and eventually sold on in the past: Sennheiser IE 80, IE 800, IE 800 S; Shure SE 530, SE 846; Ultimate Ears UE 900; Fischer Amps FA4E-XB, Rhapsody; Jays Q-Jays (current version); EarSonics SM64; HIFIMAN RE-600S. Comparisons are thus from memory, but I'm pretty confident this does not effect things that much as many of those IEMs are ones I used for a very long time.
Why are all these now gone? I intend on going wireless only when it comes to IEMs. For me portable audio needs to be truly portable and nothing is more portable than wireless. Home setups are a different matter entirely, but on the go I want something that gets out of the way and disappears. This is actually the main reason I applied for this tour: the CL2 seemed to me to be one of the ground breakers when it comes to finally getting high end sound quality in a wireless setup. I might be missing some products, but from this point of view I see it its main competition being the AKG N5005 and Beyerdynamic Xelento which both come “wireless ready”. Both are however more expensive than the CL2. Unfortunately I haven't heard either, so I can't make any comparisons there.
As for my tonality preference, out of everything I've heard I consider the Sennheiser HD 600/650 and the Focal Clear to be the best tuned headphone audio products thus far. In the IEM world the Sennheiser IE 800 S takes the crown. From this you may guess that I value a smooth frequency response with mids and treble that do not have any major spikes. Ideally a headphone needs to be able to handle all kinds of music. Being genre-specific is generally a bad sign: the original Sennheiser HD 800 likely being the most famous example.
Now I know many audiophiles are at the very least, well, let’s say conservative when it comes to accepting wireless audio. After all lossless is considered the standard and yes, there is a small difference between modern lossless and lossy files. The difference however in my experience is definitely not as big as is often claimed and and the very least it’s very difficult to hear on anything most mainstream music. Classical, vocals and other genres with minimal compression are a different topic entirely though, in those the difference is much easier to hear. In any case the AAC (and others) codec of today is not the same as five years ago and huge advances have been made in both cods and Bluetooth technology. In other words the sound quality gap between wireless and wired is getting smaller day by day.
The CL2 however strikes the ideal balance: it caters to the traditional audiophiles by offering a wired option (two actually, one cable is for balanced use which many no doubt will appreciate) along with the wireless, so everyone can make up their own mind which one they want to use. This is just my guess, but I’m betting a lot of people will start using these wired and eventually slowly move into using them almost exclusively wireless...
FIRST IMPRESSIONS
I always knew RHA had build quality locked down. It’s pretty obvious: just look at the build materials, online videos and so on. In other words I expected to be impressed with the unboxing and surely enough I wasn’t disappointed. It screams high end and quite frankly makes a mockery out of many competitors. The way the box opens has a bit of an Apple style vibe with the IEMs being in the middle with their cables disconnected. Let’s check out the accessories first: there’s the wireless cable, two wired cables (one copper 3.5mm and one silver-planted 2.5mm balanced), a carrying pouch, an airline adapter and a selection of tips (more specifically a mix of double-flange, silicon and Comply ones in different sizes) on a metal tip holder that works surprisingly well.


The first surprise however were the IEMs themselves. They are much, much smaller than I thought they would be judging by the pictures. The form is quite close to the classic Shure/Westone (+ Earsonics SM64) style, which is actually my favorite shell style. It’s a classic with a good track record. You can already guess how well the shells fit my ears (and I’m pretty sure they will fit most people really well; better than many other designs), but what isn’t apparent in the pictures is how nice these feel. The RHA website mentions that these are built from ceramics and these do indeed have a similar feel as the Sennheiser IE 800, although the CL2 feels more solid, weightier in a positive way and somehow tougher. This is quite a surprise considering the CL2 weighs 9 grams vs. IE 800’s 8 grams without a cable. These are basically built like a tank and feel more or less indestructible, although I have no idea how well these can take hard hits against concrete and so on (with IEMs this expensive that shouldn’t really be happening though). My guess is that the ceramics layer is thicker than on the IE 800 series since they also feel quite cold before warming up. Or it could just be because the material is different: the ceramics they are using here is zirconium. Ceramics in general is probably the ideal material for IEMs since it is extremely stiff and durable, the downside being that it’s expensive to work with and is thus only seen in higher end products.
As for the design, the CL2 looks high end yet minimalistic. It won’t gather any unwanted attention on the subway like perhaps the Beyerdynamic Xelento would. Now aesthetics is obviously a very subjective topic, but personally I’m a big fan of this approach. They don’t draw attention to themselves, look good with any clothing style and aren’t really that divisive compared to something more brash looking.


As for the cables, the wired ones I feel are bound to divide opinion. They are quite thick, heavy and the colors are a far cry from the minimalistic and understated look of the IEM itself. Some will love them, others will feel they are too thick and difficult to handle (and may not be a fan of the aesthetics). I personally fall into the latter group, although I must admit the silver cable to me looks much better than the copper one. Hopefully RHA will sell the silver one in a single ended configuration someday?
The wireless one is a different matter entirely: it follows the same minimalistic design philosophy as the IEM itself and well, it just disappears. The design is beautiful. The plastic/rubber mix feels nice to touch, it doesn't feel cheap in any way and is just something that looks like it belongs with the CL2. It initially feels a bit heavy when you pick it up, but when actually wearing it the weight distribution is so good that it basically disappears. The wires coming from the battery section are also just the right length and do not to hang out in an annoying way. It's also worth emphasizing that it has a USB-C port for charging. Finally... Audio for whatever reason has been very slow to adopt USB-C despite its obvious advantages. The Chord Hugo 2 for example still uses Micro-USB, which if you ask me diminishes the value of the product somewhat. Micro-USB has a habit of breaking down and is just very flimsy feeling in general. You’ll find none of that with USB-C plus the cable orientation doesn’t matter anymore. The cable charges quickly and I didn’t have a problem with running out of power during the day. Never experienced any audio cutouts either and the pairing process with an iPhone X was a breeze. I unfortunately forgot to measure how long the cable charge lasts, but hopefully someone else from the tour can do that since it’s probably something a lot of people want to know.


These IEMs use MMCX connectors. I’ll be honest with you: I’m not a fan. I’ve had a UE 900 and Shure SE 215 that both used this connector and developed audio cutouts to the point where I found using them very annoying. However on the other hand I had the Shure SE 846 for quite a long time and they never had a single issue despite using the same connector. I’m hoping the CL2 will be similar, but in addition to potential cutout issues my main grievance with this type of connector is the basic swiveling function they have. In my experience it doesn’t improve finding a good fit, it makes it more difficult as you have to adjust them more often. With a classic 2-pin connector like on the EarSonics models you just bend the memory wire to suit your ears and forget about it: since it won’t swivel they will always feel the same when you put them on. This is however a theme that divides opinion a lot, there are also a lot of fans of this connector. That being said, however one feels about MMCX in general, fact is that these have more or less become a standard in the industry so from that point of view I understand RHA going this way. For me it’s definitely a minus though; even if they never develop cutout issues, I just don’t find MMCX cables as comfortable/solid feeling (with over ears IEMs) compared to the traditional 2-pin connector that’s used in many custom made IEMs and also some universals like in the EarSonics ones.
As for the included tips, well, with universals it’s always down to luck. When I saw the tip selection I was pretty sure I wouldn’t encounter any issues, but to my surprise I could not get a decent seal with any of the double-flange or silicon tips. Only the Comply ones seemed to seal, and those aren’t tips that I would normally use just because they are slow to put on, wear out fast and because of that just aren’t all that suitable for portable use if you ask me. I'm not sure, but the nozzle looks quite similar to the classic Logitech style on UE 900 so I was left wondering if perhaps the UE 900 tips would fit these well. Unfortunately I don’t have them anymore so I couldn’t test. Don’t get me wrong, the Comply foams feel very comfortable once they settle in, but for me IEMs need to be used with silicon tips so you can quickly take them out and put them back in without having to replace tips that often. Hopefully RHA will expand the silicon tips selection in the future, although I have to say it’s not currently bad at all (instead it's better than on many competitors like the IE 800 series); I was just unlucky.
Unfortunately the CL2 does not feature RHA’s tuning filters. This has two downsides: first of all if the stock tuning isn’t to your liking you are out of luck (unless you EQ them, but EQ is not something I am willing to do with portables unless there's a product specific app that uploads the choices to the IEM itself so they work universally), but also there is now no 100% safe ear wax filter (except on the Comply tips which have one, but that’s another matter) on the IEM itself. On an IEM this expensive I would have prefered to see some system that is 100% safe. There is however a metal spiral part that likely helps keep ear wax away from the grid section.


Once I finally pressed play I was instantly impressed: bass was very deep and punchy as expected, but it never overshadowed the mids. Resolution seemed high and soundstage was far larger than I expected from a closed design planar driver. Even the treble extension – traditionally a weak spot with planar drivers – was very good. However as I listened to different songs I noticed there was kind of a rough feel to the sound as if the drivers hadn’t really settled in yet. So I left them to burn in and continued later. It turned out this was a smart move: these were apparently straight from the factory without much (or any) burn in and they did indeed settle down a lot. So a note to all future listeners: burn these in for at least 24 hours before starting to listen. Oh and for the record I’m not even a big believer in burn in, but planar drivers seem to be an exception (I’ve had similar experiences with full size planar headphones; balanced armature IEMs on the other hand never seem to need any burn).
That being said, first impressions in audio are notoriously unreliable. If something really wows you the first time you listen to them it may even be a bad sign: the HD 800 is a good example. It’s probably the best case study of a product that creates an almost unbelievably good first impression when listened to which carefully chosen music, but then in the long run many end up selling due to the treble spikes (or lack of bass). In my experience high end audio products typically have at least some major flaws, it’s more or less to be expected. Finding an all rounder with a smooth frequency response is extremely rare and that's the ideal to aim for. That’s why the Sennheiser HD 600/HD650 series are still so popular even after all these years: they may sound unremarkable at first, but they have no serious flaws and offer some of the smoothest frequency responses on the market. The IE 800 / IE 800 S are also interesting in this regard: the original IE 800 has too much bass and treble for a lot of people making it good for outdoors use in noisy areas, but a bad for indoors use. Or a genre specialist for pop/hiphop/electronica, depends on who you ask… The IE 800 S took a different direction and toned down both the treble and bass leaving a very smooth frequency response, but on the other hand some will feel it lacks the “fun” factor the original had. But let’s finally get to the more in depth sound quality parts of this review...
RESOLUTION AND SOUNDSTAGE
Planar drivers aren’t really generally known for being the most resolving ones. They have a lot of other virtues like class leading bass performance, but raw resolution in my experience just isn’t one of them. That’s why I was very surprised to notice that these are actually very resolving IEMs. Not on the same level as the IE 800 S for example, but clearly superior to your average 300-400 euro price range IEMs. Now I haven’t heard that many planar headphones, but I would say these are more resolving than the Audeze LCD-2 Classics (which I’ve owned) or likely even the HIFIMAN HE-1000 I’ve auditioned. That being said, I’m not completely sure if this subjective feeling of a high resolution is entirely down to “real resolution” or if it is partly enhanced by the boosted upper midrange. My guess is that the truth is somewhere in the middle: that this is an exceptionally resolving planar driver, but the tonality is also designed to provide some added “fake” sense of detail. More on that in the midrange section though.
The thing I expected the least out of these was hearing a wide soundstage. I know many disagree, but I’ve never heard a planar that didn’t sound at least somewhat claustrophobic and closed in. There’s none of that here, which is almost a miracle considering these are not only a planar design, but in addition to that a closed shell design. To put things short: these have a wide and tall soundstage that often makes you forget that you are listening to IEMs. Not many IEMs pull this off, so this is definitely one of the high points here. The only minus when it comes to the soundstage is that the depth is not on the same level as the rest (for example the IE 800 series is clearly superior in this regard). Instrument separation is also very good: above the typical cheaper IEMs, but not best of class. Out of everything I’ve heard that award still goes to the IE 800 series. All in all considering the technology being used here and the closed design the soundstage performance is exceptionally good.
BASS
So far so good… Now this part you probably already guess what I’m about to write. This is a planar driver after all and bass is simply what this technology does the best. This is where planar drivers excel and one of the main reasons many find it very difficult to go back to dynamic or balanced armature drivers after getting used to planar bass performance. That being said, there were also a couple of surprises here. Let’s start with what you probably do expect: yes, the bass is ultra clean, tight and goes very deep. However it also fast: subjectively there isn’t a lot of extra decay, so instead it sounds tight, tuneful and never bloated.
The surprising part here that there is no artificial bass quantity boost, which is usually common with planar drivers because it's a nice way to show of the technology. You won’t find that here. These aren’t bass cannons at all and instead go for neutrality. This doesn’t mean the bass quantity is lacking per se, but these do not have the added bass boost some IEMs have that lead to a “fun” sound tonality that often suits genres like hip-hip/electronica well. That being said while I didn't try EQ with these, planar drivers typically respond well to EQ so on a home rig at least it should be easy to add a couple of dB of sub bass for that extra kick. The official frequency response chart (although very smoothed over as official ones always are) seems to support impression. All in all these probably have the cleanest, fastest and deepest bass I’ve ever heard out of an IEM. Personally I would have preferred to have a bit more sub bass boost though, but unfortunately that option is only there with EQ. The inclusion of tonality adjusting filters would have helped here.
MIDS
This is where things for me got problematic. Now I’m a fan of smooth, linear midrange that does not have any major dips or spikes. Our ears are also the most sensitive in this area too. For me this part in the frequency response makes or breaks an IEM. In my experience IEMs that stray too much from linear here can often sound shouty, fatiguing and the realism of the vocals suffers as well. I’ll start with the good news: due to the neutral tuning the bass never, ever intrudes on the midrange. It doesn’t matter how much bass is in the mix (or how deep it goes), midrange will always stay clear of bass influence. In fact it’s not just a matter of not intruding on it, but parts of the midrange are actually boosted on this IEM to bring vocals forward. I’m again referring to the official frequency response chart on the RHA website: notice the rise beginning from the midrange (500Hz to 2kHz) and then the clear spikes in the upper midrange (2kHz to 4kHz). This spike in the upper midrange is often used in headphones and IEMs among other things to boost the sense of detail (however one can argue that it’s fake in a way), but nothing comes free: it can also make sibilance worse or just sound unpleasantly shouty/sharp on certain material. Unfortunately the midrange tuning style in the CL2 is not something I generally like and I have to say that in many aspects this proved to be a deal breaker for me. Sibilance wasn’t the issue, but the CL2 had the latter issue on many songs. On a home rig I would definitely want to EQ this down.
As it generally is with headphones with similar midrange tonality, it really depends on what you are listening to: in many albums there are no problems and the tonality may even sound subjectively better than a more neutral approach, but on many albums I found the sound too fatiguing/piercing after a while. Overall this breaks the CL2 as an all rounder for me. I would personally have preferred a more linear midrange (no upper midrange spike) at the expense of less perceived detail. Generally speaking this kind of tuning (at least to my ears) is more of a problem with mainstream genres than audiophile ones though, so it partly depends on what kind of music you listen to the most. Note however that I am probably a lot more sensitive when it comes to midrange: for example I found the Shure SE 846 midrange to be too shouty/edgy as well (not as much, but to an annoying degree). All this being said, there are of course also a lot of people who prefer boosted upper mids, so it all comes down to personal preference.
The resolution on the other hand continued to impress: vocals were often very realistic and when an album is mastered in a way where the upper midrange spike doesn’t offend, the results are often stunning. However due to the dB level difference between lower and higher mids some vocals can sound a bit off/muddled depending on where they hit on the frequency response. This is another downside to the chosen midrange frequency response tuning.
TREBLE
Planar drivers can’t do treble well. That’s at least the stereotype and to my best knowledge getting treble right is one of the main challenges when working with a planar driver (vs. getting bass right on a dynamic). Well, this one defies the odds here and is definitely not your typical Audeze LCD-2 Classic or even the Shure SE 846 (where the treble seems to fall off a cliff pretty fast). Now the treble here isn’t the smoothest or most detailed out there compared to the highest level of competition (IE 800 S for example is on different level), but it is very impressive for a planar driver and a critical part in creating that awesome soundstage. The CL2 treble is nicely extended and that's something I wasn’t expecting to hear at all. The is a slight roughness in the treble that isn’t apparent in high end balanced armatures or dynamic driver IEMs, but it wasn’t something that annoyed me much. Due to the slight roughness the resolution here didn’t sound as it was quite on the same level as in the midrange and bass, but the difference wasn’t drastic enough to make it stick out too much.
CONCLUSION
This one is tough… From the moment I opened the box I wanted to love them. They do so many things right: a superb wireless cable design, industry leading build quality and comfort, they're priced fairly and of course the quality impresses in many ways. On the downside however it goes with the MMCX connectors and the only tips that worked for me were the Comply ones (just bad luck; I doubt many will have this problem). It’s main issue however to me is the midrange tuning that artificially boosts the sense of detail, makes certain material sound shouty/fatiguing and for me that simply breaks it as an all rounder. The treble is also slightly problematic, but that is something I would gladly take in return for getting freed from the traditional claustrophobic planar driver sound.
Would I recommend it? Yes if you have a preference towards this kind of tuning, are ok with MMCX connectors and know from past RHA products that the tips fit you well. For others I would say it’s an IEM that you need to audition before making a decision or buy from a place that accepts returns. Then again that’s what I would say of more or less every expensive universal IEM out there. To sum things up: add 1+ star if the midrange tonality is to your liking and you have nothing against the MMCX connector type. Personally however I believe IEMs need to be all rounders and I place a high value on frequency response smoothness so for me this is unfortunately (despite all its virtues) a pass. I just wish RHA would have kept their sound tuning filters technology or perhaps supported an app that can upload EQ settings to the bluetooth cable. That could have solved the most pressing issues for me (except for the Comply one, but fit with universals is down to luck).