RHA CL1 Ceramic

General Information

Optimised for use with amplifiers, the CL1 Ceramic combines two unique transducer technologies to exert unprecedented levels of control over an extended frequency range. The headphone’s CL Dynamic transducer has been engineered for bass and midrange accuracy, while the ceramic plate driver generates precise upper frequency and harmonic tones.

The CL1 also features RHA’s first high-density ceramic housings and detachable cable system with mouldable over-ear hooks, affording high levels of both durability and comfort.

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Pros: durability, liquid treble, clear sound stage, comfort, build quality, warranty
Cons: Designed for stationary audio-source or Dacamp L1


Ceramic is the most familiar material for humanity and requires many touches. This material obtains by applying high heat to raw natural particles, starting from ceramic cups to glasses, cements, optical fiber and synthetic diamonds.

It is also resistant to sudden temperature changes, does not pass through electricity, has good corrosion resistance. However, is usually broken easily. ‘Zirconium Oxide’ which improves this weakness is 8 times stronger than plastic, but it is known as a hard material to process.

The Scotland company ‘RHA Audio’ has been recognized by the US ‘Apple’ for its production philosophy, and as a co-operative company, it has delivered in-ear headphones to Apple stores around world since 2011. Now 2017, they released new ‘CL-1’ in-ear headphone using ‘Zirconium Oxide’ for high-end head-fi users.



The exterior design of ‘CL-1’ is optimized for audiophiles using a dedicated portable DAC-amplifier ‘DACAMP L1’, or an audio system for headphones. The unit's housing is made of non-oxidizing zirconium metal, which has a stylish appearance is reminiscent of titanium and has a ruggedness that does not break easily even when dropped.

Both unit houses have their logos and model names engraved on the front and back, and there is a black wire mesh duct next to the RHA logo. The nozzle part is fabricated in the shape of a whirl of aluminum metal on the wire mesh filter separately. The nozzle tubes are 4mm caliber size, so a variety of ear-tips are available for listening with.



The 'CL-1' employs a sMMCX proprietary connector, so you can alternate between a 3.5 mm stereo braided oxygen-free copper cable and a 4pin mini-XLR balanced silver core Ag4X cable. Compared to the existing MMCX method, it is more tightly coupled. The length of both cables is same about 1.5 m (59 inch) and is recommended for use with stationary systems.

The outer shell is made of high-quality material that does not adhere to dust, has good flexibility and has not been exposed to microphonic. Since the position of the Y-split point is below than normal earphones, recommend using the cinch up.

Unlike other brands of cable ear guides, spring and wire are included. The unit is firmly fixed enough to float in the air, so if you put it well behind your ears, the weight of the unit will be well dispersed, helping you to enjoy your music for a long time.


The silver core cable is designed separately for 4pin mini-XLR terminal of 'L1 DACAMP'. It is designed to be removable by pushing the black button at the top like the regular XLR. The copper cable’s polarity of 3.5mm stereo terminal is made long so that it can be connected smoothly to a portable device with thick case.

CL-1 package includes silicon ear-caps, double flange silicone ear-caps, Comply Tsx-200 memory-foam ear-caps, clothing clip, carrying pouch, and 3.5 to 6.5 mm stereo converter. The 3.5 to 6.5 stereo converter can be screwed onto the copper cable. There are two small storage compartments inside the dedicated pouch, but it is narrow space for even basic components for CL1 use.



Driver: CL Dynamic + Ceramic Plate
Frequency range: 16-45,000Hz
Impedance: 150 Ohms
Sensitivity: 89dB
Rated/ max power: 10/ 50mW
Weight: 14g

Warranty: 3 years



Overall sound signature of ‘CL-1’ pretty is analogous to weak V-shaped, with more weighted-on highs. Overall soundstage shifts two steps forward, that doesn’t make recessed layering of middles. Spatiality is expressed as if the instruments are resonating from the center axis of the listener, so that sonic brings a feeling of being opened and not confined.

Due to the feature of trebles having liquid and taut texture, in beginning of ‘Paganini Caprice No.5, Op.1’, ‘CL-1’ does not miss the long stretches of violin strings, helps to blow out intensely. Since lower highs have no tail and are expressed in dry state, the scraping expression of classical guitar strokes sounds natural. But, the detail of the snare or high-hat may sound lifeless.

While the reverberation becomes richer with lower frequency on middles, roll-off response speed is constant. Also, the middles are warmer and thicker than treble that make piano note or vocal belonged more like flat. The bass is relatively warmer compared to middles and highs, and as its band reaches upper band, it is heavier and roll-up speed is faster, so that the sonic details can be more expressed. The texture from harmonics of the brass and bass instrument represented in the sound source blow pretty well without filtration.


With mini-XLR terminal of RHA DACAMP L1, ‘CL-1’ shows deep-bass naturally boosted and trebles analytically revealed. The whole sound stage is laid-back by two steps, dynamic range and width get bit bigger. That allows instruments to be more precisely positioned so that do not overlap each other. However, “ah” vowel coloration is caused because of rapid roll-up on upper midrange.

If use the enclosed double flange silicone ear-cap together, the presentation of midrange moves one step more forward and the trebles get thicker to sound a stronger string instrument representation. Comply Tsx-200 Memory-Form including CL-1 package makes upper midrange and overall trebles closed, and lower bass smother, thus creating a soft sonic imaging ambiance that allows you to enjoy more genres of music.

'CL1' has a 150 ohm high impedance and a low sensitivity of 89dB. If the required output environment is not reached, trebles and middles of ‘CL-1’ will present wiry and tizzy sound. Strongly recommend matching it with a dedicated amplifier 'DACAMP L1' or stationary audio system capable of driving low-efficiency headphones, as has required fairly-high input-power.


Hello, I am a Head-fi product reviewer named 'Bigheadfiler' in South Korea. This review may not be perfect because it is my third English translation. I appreciate your understanding. Thank you.

The 'RHA CL-1' in-earheadphone posted on review was provided by 'RHA Audio'. And 'DACAMP L1' sample was rented by Korean RHA official distributor 'Sovico AV'. This review has been written without any restrictions as respect author's autonomous decision making.

Photo & Review by Bigheadfiler, 2017
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Headphoneus Supremus
Pros: Comfort, decent reach in bass and treble, BUILD QUALITY, excellent cables
Cons: V-shaped not for all, not really much...
The nice thing about being last on the tour is that I have the benefit of completely broken in equipment. The new smell and feel is gone. Gone through many miles and air flights, and USPS trucks and many ears filled with various stages and consistencies of earwax. Various stages of responsibilities and obligations set under the guise of "I have to get this done, YESTERDAY!"
That is the beauty of being last. I have no such pretense. I have no such obligation. No such responsibility. Kind of like when I applied for the tour....I was late, I was after the deadline...and well...didn't get onto the tour. But, as luck would have it, another dropped and I caught the RHA bug. As time would have it, I was between reviews, and successfully breaking in some of my own gear. Yiiipppeeee! It was fate. It was almost like RHA knew my Scottish heritage. I gladly accepted the spot, and waited. Other reviews and gear filled my time.
I casually waited for the arrival, and perused the reviews. Having a pair of fine RHA ma750 (non-mic), I knew of RHA's near-legendary build status. Known for a build equivalent on par with a Swiss watch, I really like the sound. A bright vibrant sound reminds me of a stalwart Scot who is friend to all at a party.
I was hoping that the sound of the enclosed gear would rival my happily owned ma750's. Reading the various reviews, all commented on that build as top notch. But when sound was discussed, the views varied wildly. Yes wildly, not widely. Widely denotes a common line in time albeit one with variance. Wildly denotes all over the place, passing that line with the speed of light, in all directions. I loved that, and awaited my take on that ride, grabbing hold late one Saturday, after the snail pace of my wait on the day of delivery (not the fault of the sender). As hours turned into MANY hours, the lateness of postal delivery...by tortoise I have no doubt, finally brought the product(s) to my door.
Hence, the time begins....A huge thanks to Nik and the RHA team for including me on the tour. I will do my best with various devices in hand to give an honest open review.
I have an affinity for the state of Kansas (otherwise known as “flyover country”). It stems from the hours and days and months I spent riding my mountain bike through that wonderfully peaceful scenery, as distraction from classes at Kansas State University (#EMAW). Far from civilization, we would just ride. Sometimes we met a rancher, but before we could be booted off his land for trespassing; we always mentioned how we had mended a section of fence for him, or cleared some brush from their fence line...something to show we cared about his land as much as he and his family. Over time our group grew to a hearty 5; but the rules did not change. We ALWAYS fixed something. The mutual respect between the rancher and our group of mountain bikers allowed us free entry onto land that few if any would visit, ever. This solitude was not lost on either the rancher or us. Ever.
That affinity to Kansas carries over the group, which shares that same name, a group I wholeheartedly recommend you give a good listen. It was this music, which was used for the week (along with many of my standards). I could not think of a better tie between the heartland, and the Scottish country. A country with a proud heritage of many items. Not the least of which is the best single malts the planet has ever known. Of that there is not debate in my mind. It is with that same fortitude, which I do believe RHA crafts their wares. Having, and still owning the ma750, I understand. If the product cannot stand up to Scottish standards, it is of no use. It is not good. Well...I can unabashedly state that the quality of craftsmanship is excellent. Top notch is a term thrown about, but would not be a shy comparison here. It is that tie between Kansas and Scotland, which gives me the tie and the right to proceed on this solitude of listening. I am within, and I do not mind.
V-shape sound. Bright highs, somewhat deep bass, bleeding into the sub-bass often. Not unpleasant, but not what I expected from a flagship. Definitely needs EQing.
Compared to the FLC8S-recessed mids, lack energy. Filter versatility and a more vibrant sound. Again, EQ needed to compete.
Compared to the Aria-not as neutral, overwhelming treble. Lack of control in bass. Aria defines warm full-even sound. CL1 has to try really hard and must be EQ'd to compete.
An intimate sound stage accompanies that “power,” from the L1 to the CL1. This is not an unpleasant sound, mind you; it is just not as open and authoritative as I expected. Running my FiiO x5iii on 80/120, through Tidal and the L1 all the way up and on high gain, yields a decently loud sound, and of good quality. Again, the V-shape of the CL1 compliments the L1. But, I am left wanting MORE…. more power, louder volume…It was not until I hit 100/120, that the sound became uncomfortably loud. Granted, my old ears do have a hearing loss, but I have not gone that high on the x5iii with anything else. That said, when running the Line Out at 120/120 on the FiiO, I am allotted a good dose of power from the L1, which then drives the CL1 the way it was meant…Full, detailed, albeit bright, I am more happily enjoying the sound.
For rock such as Stevie Ray Vaughan, this combination of full on Line Out and 2-3/5 on the L1 provides the CL1 with the necessity of power needed to portray the music almost as if one were in the crowd at an SRV concert…almost. The treble still seems a bit bright, and too far forward for my taste, but this can easily be compensated for by EQing the treble down on the L1, or whatever device you are using. That is IF you prefer a treble, which is not as hot as this.
For me though, that hotted-up treble masks the detail I like in the mids. The bass and treble squeezing it out of the way hide that support piano, or support instrumentation, while they both compete for center stage. Those that like competing ends will most definitely enjoy this competition. And I can see the benefit of this in songs such as almost any Stevie Ray song. It is after all, his guitar, and the bass line, which holds the song together as SRV’s voice shines.
As for the sound qualities of the L1, I stated before they are quite nice, and acceptable. Switching to Dave Holland and his excellent Hands album, my reactions are tamed, in a good way. Music of much better quality, allows the L1 to do its work. Paired with the CL1, I can now see the benefit of both. There is most definitely that synergy going on…the pair WAS made for each other after all…A good solid bass, paired with the forward trebles allow the Spanish guitars to play effortlessly. Recessed mids are not unacceptable here. Allowing both ends around them to come through, without congestion.
If one likes expressive treble, then this may be your ticket. Not sibilant in nature, but a far reaching treble affords the CL1 to shine (pun intended) in that realm. This is definitely a V-shape, and one can accept that if ones likes. It has been said, though that for a “TOTL” IEM, this is too much of a V-shape. I would agree; but RHA has never really been one to follow the rules. Out the window went mediocre build quality for the masses, when they came along. Out the window went a tie with a large corporation, which aides their process (one needs only step inside an Apple store and you see a variety of RHA products). Out the window went a “neutral” IEM as a flagship. RHA is playing by their rules, and I completely respect that.
If one does not like the sound, then one can EQ the sound to their tastes. This is an almost refreshing aspect. One with which you can either adhere to, or look elsewhere. I have not run an EQ as much on any of my other IEM’s, as I have with the CL1. And I do not mind.
Running the CL1 through my FiiO x5iii and Aune S6 provide a MUCH different sound, than the DACAMP L1 does. Gone is the fairly even bass and treble push. An overly bright sound, overshadowing the decent bass is had streaming Tidal and Jimmy Buffett. The bright sound might suit some, but I find the treble too much to handle. That said clarity is extremely good with this set up. So, if you like an analytically bright sound with excellent clarity, then this is a good pairing.
Repeating the sound, through the native FiiO app confirms that the triplet is quite a vibrant and bright sound. I admit it; I like a warm full sound. I adore a warm sound…it is like that Guinness, which you drink warmer than it should be, but you still love it; because it is just right. That said, I do kind of dig this cold analytical sound. This is Guinness like it was meant to be served…ICE COLD. And I’m OK with that, because I LIKE Guinness. And I must admit, I like this colder sound. This makes the CL1, quite good, detailed, with excellent separation and placement of musical note.  
*Carryover from the DACAMP L1 review*
I must say, as did @Brooko in his thorough review; that the more time I spend with this little device, the more I come to appreciate it. The more I appreciate the simplicity of plug-n-play. The more I welcome how seamlessly the RHA Team makes all of the functions work. The more I value the ability across listening/music platforms…FLAC? No problem. MP3? No problem. AAC? It…just…plays…running Los Lonely Boys (another of my all time favorites) through my x5iii, and the L1; the CL1’s simply shine. With this combination, I can bypass that V-shaped sound. I can forgive the need for POWER! There is no want for more, running these together. A benefit of the Line out on the FiiO, is that the volume is adjustable. A near unheard of feature in mid-fi DAP’s. And well worth it, in my mind. Born on the Bayou simply oozes through this combo; making me feel as if I was in a backwater open air Cajun shack of a bar. Throw a lime in a cold beer, and you are there. A superb combination, not to be diminished when one considers cost.
Combined this “set up” runs north of $1600 USD. Not cheap, and for that outlay of cash, one would hope for this type of synergy. I guess it just goes to show, that even devices, which may be less than “worthy,” to some based upon their sonic preferences, can shine as part of the whole. I’m not saying I will run right out and purchase the RHA’s no; but I AM saying that for that kind of outlay, one could do much worse.
This really does show that the CL1 performs best under the “influence” of an external power source. While not bad running solo, one truly benefits from the addition of the L1. Think Big Bird and Snufalufagus, Bert & Ernie, Statler & Waldorf from the Muppet Show; and you get the idea…solo, they really aren’t that good, but paired together…WOW! What a difference! To really shine, the other is needed.
Alone, the CL1 is adequate, but not up to the level of comparably priced IEM’s, such as my Vibro Labs Aria, or the excellent Lend Me UR Ears FLC8S. When running at this price point, one must not only compete against the other I mention; but also “hand made” IEM’s such as the Campfire Audio Nova, and equally good Lyra II. This is a crowded market, as is the DAC/AMP one…
This is not a bad thing as a consumer, mind you. But for the PR departments of competing companies, an absolute nightmare…How does one promote THEIR product over the other?! I’m not sure I can fully answer that, other than to say that as a company you must innovate…be different…apply your sound to a market, which has not been tapped yet; or at least not too much…And I do think RHA is on to something here. To combine a top quality DAC/AMP with a “flagship” IEM makes good sense. For the price of a near-entry level custom IEM, one can have a really quite decent IEM AND a very good DAC/AMP. To those with the need or cash to fortuitously think of that level; they should indeed consider the RHA CL1/L1 combo. It would be a good addition to an already existing DAP, or even to use as a desktop set up.
That said if purchasing separately, I probably would consider the L1, instead of the CL1. To make the CL1 shine, the need for equalization keeps poking me in the side…and I do not like to be poked in the side, let alone poked anywhere.
The L1 can overcome that need to tame the V-shape, or enhance it, should that be to your taste. The CL1, does indeed give a good base in which to work, and one for those who do like a V-shape. But, that should not limit those who may prefer another signature. With a good EQing, one can indeed make the CL1 work to their advantage, but it will take work. With that, I would recommend the pairing together. Or, if you only purchase the CL1, prepare to look for an external amp; it is in need of a good one.
RHA CL1 Ceramic ($449) v Vibro Labs Aria ($499)
A definite V-shape defines the CL1. Decent reach at both ends, allows the bass and treble to mostly shine. It is quite apparent that the mids take a back seat to both. If that is your ticket, then you won’t be unhappy. As for the Aria’s, the signature is more even across the board, with excellent clarity. Vocals definitely shine with the Aria, and they are quite good at representing that sound. With an overall sound on the warn side, this is my go to IEM. I see no reason to move up the “chain” any higher. The sound stage is bigger, too. While the CL1 tries to cover that lack of mids with elevated ends (verified by Brooko and his excellent sonic findings), and nearly pulls it off. I do like the sound signature, but to be completely happy, I would need to equalize the CL1 pretty heavily for my tastes. Something I do not have nor need to do with the Aria. To me, the winner here is the Aria.
RHA CL1 Ceramic ($449) v Lend Me UR Ears FLC8S ($309)
I came across a loaner pair of FLC8S’ and I am glad I did. I now own a VERY lightly used pair of my own. Complementing the Aria quite nicely, I am struck how from one day to the next I can be happy with either. Granted, with the ability to change the umpteen filters, you would be hard pressed to NOT find a sound, which you like. I currently run the black-red-gunmetal combo (from outside to nozzle), because I like the bass the FLC’s pull. This is where they best my Aria…bass…And a top quality bass it is. Far reaching, and sonically deep/correct (to me); the FLC is a steal for full retail, let alone a used pair. During my review, I lost my pair…I was so despondent that I nearly purchased a new pair on the spot. Luckily, I found them in a box of Vanilla Wafers, which I had taken to school…cue the Crackerjack jokes…That is how much I liked the FLC8S. The complementary synergy with my Aria, makes both better. I cannot get enough time for either…
That kind of synergy evades me with the CL1. Only when I match the L1/CL1 combo does it come close to that level. But alas, it does not. It is good, and as I said, those with more neutral tastes will find the pair quite attractive. With the tuning ability of the L1, one can ALMOST overcome the deficiencies…almost.
RHA CL1 Ceramic ($449) v AudioQuest Nightowl ($699)
Not really a far competition, but what the heck, I did it, and I’m glad I did. I will say up front, that I am in love. I am in love with the sound of my Nightowl’s. A very different sound than my favourite IEM’s, but that is one of the points in my love. An almost holographic sound signature provides me with a wonderful alternative to the Aria. One, which is in complete complement. Decent bass, good reach in the treble, and mids, which are allowed to shine for what they were meant…honest and true. The NO allows the music to shine, sitting quite comfortably in the background. And I like that. Emminently comfortable, and a sound (to me) second only to the Focal Elear, which I was lucky enough to use as a loaner. So, as I said not really a far comparison. But one I made to make a point. A point, in that for the near-same-price (actually less) I can come away with the Nightowl and the FiiO A5, and be quite happy. Happier than I am with the CL1/L1 combo. Again, YMMV, but what with the multitude of options, the CL1/L1 combination is an excellent one to consider.
You might think that will all of my gut punches, and near-denegration of the RHA’s, that they are not good. That would be false of you to believe. Here is why. I still own (OK, my son just absconded with them…) the RHA ma750, and like them. As I said, they were taken from me, but my son now enjoys them. As he should, they are a very good open sound, which competes well at its price level. The same is what I will say of the CL1/L1, both individually and in combination together.
Taken separately, the CL1 is an honest attempt at making an affordable flagship. Albeit one with a V-shaped signature, which may not appeal to all. I get it, I understand its calling. I respect that, and would highly recommend to those that enjoy a V-shaped signature to give them a listen. Even if you prefer a more flat response, you can EQ-out the imbalances; and enjoy them. When you combine the CL1 with the L1, you have very good mid-fi combination, which can compete with other similarly priced options. The two were meant for each other, and that alone, might be worth a look…taking the consternation out of piecing together a combo might just do that. Impeccable build quality to boot, and you will be hard pressed to best this for the sound signature they provide.
I want to thank the RHA Team for including me on the tour. I do love trying new gear; especially gear, which is out of my “comfort zone” so-to-speak. Gear, which after careful analyzing I would recommend most take a look at if ones taste, might run on the more V-shaped side.
Dobrescu George
Dobrescu George
I see you're still in love with your X5 and Night Owls! 

Interesting that you like CL1 - I wish I give them a spin sometime as well. I am curious to say the least! 


Headphoneus Supremus
Pros: Excellent extension, superb ergonomics and build, great cable, high level of detail retrieval, bass texture
Cons: Treble is far too hot for my personal preferences, can sound thin without serious amping, too unbalanced for a true flagship sound signature
RHA CL1 – initial impressions
Reid Heath Audio are a Scotland-based manufacturer who will be familiar to iFans, with their T10i and T20i all-metal IEMs being prominently displayed in Apple stores across the UK. Their products have been firmly aimed at the “consumer” end of the market, with models like the MA750 and the T-series occupying the very competitive pricing sectors between £50 and £200. As part of their recent world tour, I had the chance to hear their first foray into the more serious audiophile end of the market with their new CL1 Ceramic IEM, a hybrid DD/piezoelectric tweeter design encased in a fully ceramic housing and requiring more amplification than the average iDevice to get the most out of the included technology.
Tech specs
Driver type: Single DD + piezoelectric wideband driver
Frequency range: 16Hz – 45kHz
Impedance: 150 Ohms
Sensitivity: 89dB
Weight (w/o cable): 14g
As the current “flagship” in the RHA line, the CL1 comes in packaging that wouldn’t look out of place being wrapped around a popular fruit based audio product (handy, as one of their main retail distributors is said fruity merchant). The box is a large and sturdy black affair, with a good picture of the beautiful ceramic housings on the front and some serious technical breakdowns scattered around the remaining sides. Sliding the cover off, and you are presented with a hard carboard box which opens in “book” style to reveal a booklet about the CL1 on the inner front cover and reveals the IEMs, nestling in a thick black foam cutout. The initial impression screams quality and attention to detail, with the CL1 feeling like it demands every penny of its c. £350 pricetag.
Pulling the foam layer out that the IEMs rest in reveals the remainder of the contents – further booklets containing info and the warranty card (both in nice black cardboard boxes), a standard RHA zippered carry case (about the same size and shape as a man’s wallet) and the two cable options (balanced and unbalanced) sitting in their own little chambers. Completing the loadout is a 6.3mm stereo adapter, sat in a bed of foam like the IEMs. Again, quality appears to be the order of the day here – opening the carry case to reveal the generous tip load out (all packaged individually in their own shrink wrap bags) also reveals a thin metal credit-card sized sheet built to hold all the tips once unpacked, ensuring that you can carry the full array of earplugs with you in the carry case at all times in some form of order. Overall, the packaging is well thought out, premium quality and gives a very good impression of the care and attention that has gone into this aspect of the product.
Build quality and ergonomics
The CL1 are moulded from a ceramic compound, which is harder and less resonant than their normal metal shells according to the supporting literature. The ceramic material feels exceptional to touch, with a super-smooth and glassy finish to the grey/black exterior that makes the IEMs look almost like ear-jewellery as opposed to audio gear. The finish is also top-notch, with everything looking smooth and precise, with the logo neatly etched onto the outer shell in an understated and classy way.
The design of the shell follows their T10 and T20 models, with a small coffee-bean shape and a slightly angled metal nozzle, designed for over-ear wear. In practice, the CL1 fits into my ears as well as anything I have tried or owned, with a nice sense of solidity once in place and allowing me to get a great seal with the provided Comply tips. The cabling does come with RHA’s take on memory wire for the over-ear sections, which I’m not usually a fan of, but the plastic jacketed implementation on offer here does its job well, not interfering with my glasses when I wear them and keeping the IEMs seated firmly at all times. Moving further down the cable, the build quality and overall aesthetic effect is fantastic, with both cables having a multi-braid design with a flexible plastic sheathing to give a flexible, non tangling cable (for me, anyway) that sits nicely, exhibits practically no microphonics and looks like a top-end aftermarket cable. I am not a massive believer or disbeliever in the power of cables as they affect sonic quality (I am sadly too poor to spend much money investigating this either!), but if RHA ever brought out a range of cables with standardised connectors rather than their own sMMCX variant, I would certainly consider purchasing one for my other MMCX iems.
Sound quality
Test gear:
LG G5 (with HiFi Plus 32-bit Sabre DAC add-on)
Hifiman Supermini / Megamini
RHA Dacamp L1
Fiio X7 (with AM2 module)
Test tracks (mainly 320kbps MP3 or FLAC/Tidal HiFi):
Nathaniel Rateliff & The Night Sweats – S.O.B. / Wasting Time
Blackberry Smoke – The Whipporwill (album)
Slash – Shadow Life / Bad Rain (my reference tracks for bass impact and attack, guitar “crunch”)
James Bay – The Chaos & The Calm
Sister Hazel – Hello, It’s Me (bass tone)
Chris Stapleton – Whiskey And You
Elvis – various
Leon Bridges – Coming Home (album)
Foy Vance – The Wild Swan
Daft Punk – Random Access Memories (album)
Aerosmith – The Definitive Aerosmith
Mavis Staples – Livin’ On A High Note
Twin Atlantic – The Great Divide / GLA
The Darkness – Permission To Land
Led Zeppelin – Mothership
Shawn Mullins – Soul’s Core
Sammy Hagar & The Circle – At Your Convenience (live album for audience sounds)
General impressions on the sound signature
The CL1 is billed as an IEM that needs amplification, and (barring the Pinnacle P1), this is the first IEM I have tried that definitely does need the help of a sturdy amplification system to bring out its true qualities. Like listening to music on a mobile phone or Sony EU-limited DAP? Not with this set of in-ears. Once you have properly boosted the signal coming in through the cabling, the true character of the IEM comes to the fore. The tuning RHA have gone for on their flagship is a sharply defined and unforgiving sound, with a slight hint of warmth in the bass which gives a little substance to the lower end but does nothing to blunt the scalpel-edge of the higher midrange and treble. Despite the obvious technicality, the treble tuning is a bit of a curate’s egg for me, being too sharp and piercing to be enjoyable for extended listening. As a listener with a natural preference for smooth and clear tuning over fizz and shimmer up top, that isn’t surprising in itself, but even treble-heads will find this a little bright in its current incarnation. To be able to listen for any length of time, I used the excellent Dacamp L1 that came with the tour package to cut between 2 and 3 dB from the treble to bring it within the bounds of listenability for me. Most comments that follow in the below sections are based on a treble reduction of 2 dB, so please bear that in mind.
Difference between single ended and balanced operation
Due to some serious issues between my PC and the Dacamp (and a non-functioning OTG cable for my USB-C toting phone which I am waiting to replace), I was only able to briefly test out the balanced operation compared to the single ended sound through the Dacamp, as after one three hour listening session my PC decided to give up the ghost and cease working with the Dacamp again. I don’t feel this is long enough to offer any concrete opinions on any major differences between the two modes of operation – opinion seems to be split on the benefits this offers, and to me, there seemed to be a little extra thickness to the sound, but that may just as easily have been expectation bias as anything more concrete so I will have to leave that to the other reviewers on our little world tour – for simplicity’s sake, please assume that the impressions below relate to single ended operation.
The first thing you notice with the treble is the crispness and definition of the higher frequencies, with a soaring presentation and practically limitless extension as it works up through the range. Like its younger brother the CL750, I truly believe that the CL1 is an IEM that can produce sounds only dogs can hear if it happens to be there in the music, with an effortlessness to the really high range that leaves you with no doubt that the piezoelectric driver tech is just getting started where your hearing finishes. Sense of location and “room sound” is exceptional with this IEM, with the drivers giving you an excellent feeling of being sat nearby when listening to acoustic guitars or singers, picking up on the imperceptible audio cues in the sound to flesh it out in your head nicely. In fact, the only IEM I can remember hearing with a similar effect is the Vibro Labs Maya, so in this aspect, the CL1s are definitely impressive.
Listening to “Starlight” by Slash, the dissonance of the opening guitar motif is just inside comfortable, sounding edgy and defined. Myles Kennedy’s falsetto also comes across hot but enjoyable, with a thin but crystal clear definition to the chorus. Strangely, the power in the high vocals seems to overshadow the percussion in this song, which “tssk” crisply but then seem to evaporate into nothingness rather than decaying more naturally.
Going hunting for harshness (as opposed to sharpness), Chris Stapleton gives my eardrums the usual indicators, with the sound sans EQ giving a touch too much rawness to be enjoyable for any length of time. The texture of the singer’s voice feels almost hyper-emphasised, with the chorus drilling into my inner ear and taking me out of the soulful vibe the rest of the song inhabits. There is a leanness to the highs that emphasises detail and texture, but without the accompanying body, it becomes too sharp for my personal tastes, crossing the line into audio anorexia in an attempt to have the most defined sonic cheekbones on the market. Using the Dacamp EQ does help, but in doing so, it takes a little of the glorious air and openness out of the sound at the same time.
Switching to some electronic music, the results are better, with “Nobody To Love” by Sigma and “Go” by the Chemical Brothers benefitting from the sharply defined sounds to give an airy and engaging upper end to the respective tracks.
Again, texture and definition are the order of the day here, with a rasping detail to vocals and beautiful if thin sound to acoustic guitar and strings that can be quite compelling with the right track. The vocals sound a little overshadowed by the comparatively warmer and chunkier lower end and the rapier-like high end, so sit a little further back in my ears in something approximating a U shape for me. With the right acoustic or simple orchestral music, the quality of the dual-driver setup can really be brought out, with “The Trooper” by 2Cellos and “Saint Is A Sinner” by Slash sounding delicate and textured, shimmering through the earpieces with energy and life.
The leanness of the sound can tend to leave the overall presentation feeling a little analytical in the vocals, without enough body to the sound to really drive home the emotional connection the texture and detail are reaching for. Similarly, electric guitars give more crunch than an explosion in a breakfast cereal factory, but don’t have the accompanying “whoompf” of physical impact to go along with the pyrotechnics. Technically, the midrange is detailed and carries good energy, but could do with a little more body. One flaw that is apparent for me is in a similar vein to the CL750, with a spike in the higher-midrange through to the lower treble that can make some male singers sound unpleasantly harsh and seems to cloud some detail from the higher ranges. On a badly mastered or sibilant track these can be downright painful, turning a nice session of ear massage into open-skull brain surgery at the drop of a hat. The fact that both new models exhibit the same tuning indicates to me that either it is a “side-effect” of the new driver tech they haven’t smoothed out yet, or a deliberate tuning decision. The spike can be supressed by judicious use of EQ, which tells me that the IEM should be capable of a smoother ride, so the choice to bake so much of a jump in the frequency range into the basic tuning is a little confusing to me.
The bass is a reasonably lean but textured affair, with a little lift above neutral but no massive feeling of body or presence. Kicking off with one of my favourite tracks for mid-bass texture, “Bad Rain” by Slash highlights the capability of the driver in certain areas, exhibiting good extension all the way down into the borderlands of the sub-bass region. It also sports a texture you could strike a match one like Clint Eastwood’s stubble, all definition and snarling cool but not a massive amount of body, just enough to rise above flat without warming the sound too much.
Looking for liquidity and smoothness, “Hello, It’s Me” by Sister Hazel is up next. The wideband DD shows good speed and control with this track, giving a great rasp to the vibrating bass guitar strings. On IEMs like the Campfire Vega, this track can sound like someone pouring molten chocolate into your ears – with the CL1, the sensation is less molten chocolate and more warm milk chocolate milkshake in terms of filling the soundscape, keeping a nice sense of liquidity but painting everything with a thin layer of bass rather than a more viscous coating.
Switching to electronica, “Nobody To Love” by Sigma has a crisp and bouncy bassline presence, but needs a little bass boost from tone controls on the Dacamp to really command the track. The normally thrumming sub-bass sounds more polite and restrained, highlighting not so much a lack of extension into the sub frequencies as a similar lack of real “meat” to the sound, in keeping with the mid-bass. Trying “Heaven” by Émile Sande, which opens with a solid sub-bass rumble and pins it to the foundations of the track, the CL1 is again polite rather than throbbing, the sub-bass not quite filling the soundscape like it should. Moving up through the frequency range, the rest of the bass is crisp and defined, however, with a decent kick to the drums and good overall feeling of speed.
Overall, the bass is a lean, mean creature on this IEM, with plenty of detail but just lacking a couple of lbs around the middle and lower portions to really hammer home the quality. For people who value a leaner “audiophile” style bass, this will probably be close to perfect, but for my personal preferences, it is just a little too much rasp and not enough thud to help me engage with non-acoustic styles of music.
The soundstage on the CL1 is a decent size, extending outside my ears in all directions in a nicely spherical arrangement, with as much depth as width. Helped by the supersonic extension, direction cues are very good with this IEM, with a precise sense of placement of instruments across the soundstage to my ears. In terms of separation, the technical prowess and overall sharpness of the sound in the higher registers helps to keep the instruments nicely distanced, with multiple strands of guitar or keyboard riffs winding around each other without blending together, allowing the listener to quite easily pick them apart with minimal effort.
Tip and cable choice
The CL1 ships with two of their proprietary sMMCX cables as standard, one in “standard” 3.5mm TRS configuration using OFC copper, and one using silver cabling and using a 4-pin balanced connector for use with the new Dacamp. Both cables are gloriously thick and supple, making the usually stellar looking ALO Litz cabling from my Campfire Audio IEMs look positively anorexic and stiff in comparison. The finish on both cables is top-notch, with solid metal on the Y-split and cable jacks, and a well-implemented memory wire earhook that sits nicely behind the ears without the need for too much moulding. The cables are high quality and beautiful looking, with minimal microphonics and an overall impression of quality that will happily hold up against plenty of after-market options without looking inferior. If it wasn’t for the bespoke sMMCX termination, I would say these are the best stock cables I have come across yet, pushing ALO/Campfire Audio hard in overall quality and sonic capability.
Tips are the standard RHA fare, with multiple dual-density silicon options, some dual flanged silicon and a smattering of Comply Tx tips. For my personal preference, the dual-density silicon fitted beautifully but did nothing to alleviate the excess treble present in the base IEM tunings, so I found the best synergy with the Comply Tx-comfort series tips that are included. The “Waxguard” covering takes a little edge off the highs, still leaving it with plenty of crunch and bite but taming it just enough in tandem with some heavy EQ from the Dacamp for my personal preferences and also allowing the best seal in my ears.
Power requirements / DAP synergy
At 150 Ohms and 87dB sensitivity, there is no doubt about the fact that the CL1 is definitely an IEM that requires amplification to sound good. It even says so on the front of the box. That isn’t to say that the CL1s can’t be run from a more modest setup – my LG G5 manages to get passable volume out of them at close to full tilt on Neutron Player. What it doesn’t get is the proper sense of dynamics and fullness to the sound that the Cl1 is actually capable of. Putting additional power through these IEMs helps fill out the sound in the mid-range, and retains the extension on the treble but helps smooth out the sharpness to listenable levels. Without gas, the sound signature sounds thinner and almost shrill with certain music – with am more sturdy source, the “true” signature comes out, the treble settles down and the midrange comes fully out to play. As you would imagine, the RHA Dacamp L1 pairs well with these IEMs (in fact, due to their proprietary sMMCX connectors, this is currently the only option if you wish to run the CL1s in balanced mode to take full advantage of the extra horsepower), with the CL1s singing properly on the “High” gain setting without sounding forced or overloaded.
Another surprisingly synergistic combination is provided by the new Hifiman Supermini, with the higher than usual voltage output of the tiny DAP bridging some of the power gap between standard phone/DAP outputs and the beefier Dacamp L1 and producing a more nicely rounded and pleasing sound out of the CL1s. The little brother of the new Hifiman range (the Megamini) also does surprisingly well here too, requiring a good few more volume steps to reach the same output but again sounding a little fuller and less harsh than the G5, sitting between the phone and the Supermini.
Fiio X7 – like its little brother the CL750, I didn’t find the pairing with the AM2 module on high gain to be particularly pleasing for my ears, even with the extra power from the “mid-range” amp module. The tonality of the music sounding a little too etched for me – for my ears, this isn’t a pairing that goes together particularly well.
Overall conclusions
Like its younger sibling the CL750, I think the CL1 is more a sign of the potential capability of the driver tech that RHA are debuting here rather than the finished article. It provides excellent high end extension and superb crispness and definition, but then overcooks it a little further down the scale and buries some of that crystalline beauty in the hot and harsh lower treble/high midrange. The bass is textured and capable, with a little warmth but not quite enough body for my personal preferences – without the midrange spike, they would blend much better with the rest of the frequency ranges to give a nice coldness and analytical spin on the sound overall, with just a hint of substance. As it is, they aren’t thick enough to warm the lower end enough to overcome the more recessed midrange. This isn’t to say this is a bad IEM if you like crystal clear and icy cold detail, with a king size serving of heat. For some people, this will provide the sort of sound that is more commonly brought up when discussing things like the HD800, with the undeniable ability of the tweeter bringing something different to the party than most current “flagship” offerings. As a flagship, the beautiful build and top notch cable and packaging are certainly befitting of the tag, and if RHA can take a healthy dose of sharpness out of the high mids and send the bass on a strict gym regimen to pack on some weight, they could have a real contender on their hands. In its current form however, it is a little too lean and a lot too sharp for my personal tastes – I look forward to seeing where RHA go with this technology, however, as I don’t think the story is quite over yet.
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Reactions: Brooko
It hasn't, but at the same time it's not the lightest in all their IEMs (CL750). If you want hear strong deep bas and some serious quality, get the T20 (not T20i).
How many hours of break in time is on them at the time of this review?
As they were a tour unit, I don't know - I think I was around 4th on the tour schedule, so a minimum of 100hrs prior to my time with them would be my guess. I didn't notice any difference in sound during my listening as the hours racked up anyway.


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