Review: RHA CL1 – Specific

Price & Accessories


The price of the RHA CL1 is 449.95€ or you can get it in a combo pack with Dacamp L1 for €949.95. Yes that’s serious money for an RHA IEM but looking at today’s market and the prices companies are charging for universal IEMs, that’s actually not so bad. We already know they are perfectly built and have great comfort, something that’s not even always the case with more expensive IEMs.

The RHA CL1 comes delivered with two sets of cables:

1 Braided OFC Cable with the special sMMCX connection, and finished with a straight 3mm plug.

1 Braided AG4X Balanced cable, of course also with the sMMCX connector, but this one is finishes with a mini XLR. That does make it more difficult to use any other balanced amplifier with the CL1, so I do regret this choice somewhat as you now need an adapter to listened to the CL1 in balanced mode from another amplifier.

Of course RHA is also shipping a 6.35m adaptor for the unbalanced cable. Next to that you get a large selection of silicone tips and Comply Foam tips with the typical RHA stainless steel tip holder. Tips included are:

  • 6 pairs, dual density ear tips – S x2 / M x2 / L x2
  • 2 pairs, double flange ear tips – S x1 / L x1
  • 3 pairs, Comply™ Tsx-200 Comfort Plus ear tips with Waxguard™ – S x1 / M x1 / L x1

Finally, the CL1 also comes with a protective case with clothing clip, a cleaning cloth and one heck of a manual and informative folder.


If you look at the specs below you’ll notice the RHA CLA has an impedance of 150Ohm and a sensitivity of only 87dB. That means it is hard to drive but that isn’t a secret and RHA has made that clear from the beginning. Like said earlier, that’s exactly why they launched the Dacamp L1 at the same time. I’m a bit disappointed in the choice of the mini-XLR termination as this seriously limits the use in balanced mode with any other portable amplifiers, unless you’re willing to invest in an adapter. Maybe RHA could have added this adaptor in the box as the standard nowadays pretty much is the 2.5mm termination, although Sony and Sennheiser are trying to introduce a new standard balanced plug.

So if you’re not planning on carrying around a portable amplifier or using a more powerful DAP, then you probably will have an issue driving the CL1. In that case it’s not recommended to go for this IEM but the T10 and/or T20 IEMs will be the earphones to look at.

Technical Specs

DriversCL Dynamic + Ceramic Plate
Frequency range16-45,000Hz
Impedance150 ohms
Rated/max power10/50mW
Weight14g (without cables)
CableBraided OFC (sMMCX-3.5mm), Ag4x (sMMCX-Mini XLR)
Connections3.5mm/6.35mm, 4-pin Mini XLR



The following impressions of the CL1’s sound are based on the combination with the RHA Dacamp L1 in balanced and in single ended mode, fed by my laptop and with Roon as transport. For impressions on how the CL1 sounds in SE-configuration with other amplifiers, see the “Amplification” section below.

Single Ended Mode

Even on low gain, the L1 makes the CL1 play loud very quickly and my listening level is just under 2 (out of 5). The first thing you notice is how powerful the CL1 sounds with the L1 as source. The CL1 has great impact from top to bottom and the sound is extremely dynamic and energetic with a high level of detail. The CL1 sounds clean, clear and very fast. The L1 controls this CL1 like nothing else and the CL1 (like on all the other sources and amps I tried) is dead silent.

The CL1 sounds spacious but not overly so and it has great separation. From bass to highs, you get a rich and nicely layered presentation. While other amps sometimes make the mids section more in the back, the L1 manages to get it closer to that of the bass and treble but it’s still a little lower and less “represented”. There’s also no denying that the CL1 is a more treble accentuated IEM but I don’t think it’s overly focusing on treble in a way it becomes unpleasant to listen to, although it does depend on what amplifier and source you’re using it with. If you’re not in to higher mids and treble then this CL1 will probably won’t be the IEM for you though.

Bass is tight and fast and goes deep when needed. Bass (no boost) is almost neutrally present but when called upon will be there to impress you. That mostly is so because of the little mid bass bump you can see on the Frequency readout. Bass doesn’t really have that sub presence and you get quality over quantity. There’s still enough bass presence overall to enjoy the CL1 though.

The mids are rich and clean and they have good layering but as we said, they’re a little more in the back, depending on the source/amp used. The upper mids and treble clearly have a focus in the CL1. The voices – depending on the amp/source – sound more forward and natural and as the FR curve shows, the CL1 has quite the drops and peaks in the treble section. To me it on paper looks worse than it sounds though, but yes, the treble focus is clearly there and it’s something you don’t find that often on the market when looking at popular IEMs. RHA clearly made this choice however.

Balanced mode

As none of my other amps has the same balanced mini-XLR output I have to do this part from memory. As so many other have probably said before me, the balanced output of the L1 really upgrades the sound quality delivered by the CL1. The CL1 is getting the most power and you can clearly hear it’s performing at its best level.

The CL1 really sounds more balanced from bass to highs with less peaks. It’s still spacy and the delivery compared to the single ended CL1 is smoother. To me the CL1 sounds more natural and analogue in balanced mode. Yes, the focus is still on the higher mids and treble but that’s something that won’t change unless you’ll do some EQ’ing.

Driveability (DAPs)

Straight from the Astell&Kern AK70, the CL1 has lighter and slightly more forward presentation. The volume level goes up a lot higher than with “normal” IEMs but the CL1’s bass has good body, impact and is tight. The mids are not too much to the back (depending on the recording) and the voices are a bit more forward and sometimes thinner sounding. Treble of course has a focus. Shozy’s newest Alien+ is extremely good sounding and on the MID setting it easily drives the CL1 making it very musical, detailed/rich and precise. The level of detail is very good and the CL1 shows really nice layering and depth. Voices are a lot more realistic with bigger mids. Treble of course still is very much present.

The AK380 makes the CL1 sound very clean, tight and fast. Bass is tight but doesn’t have big impact or a lot of punch. From bass to treble the AK380 makes the CL1 very rich in detail but just like with the AK70, the mids are a bit thinner (unlike on the Alien+).

The volume of the Fiio X5III goes up quite a bit to get the CL1 to my listening level but I like this pairing. This combination delivers good detail from low to high and high musicality but the bass quantity and impact are missing a little. The mids are a little more to the thinner side but not too much. Vocals sound only a little bit forward but still natural and the extension up high of course is good. With Fiio’s X7 (AM3) you get an overall lighter presentation from bass to highs but in return you get a lot of clarity and detail with great speed. If you like a bigger bodied sound, the X7 isn’t the DAP for this IEM.

While most of the dedicated DAPs have enough power to drive the RHA CL1, they all make the CL1 sound different. Personally I like the AK70 and Alien+ most as they have a good amount of body by themselves. The Alien+ is my very favourite as it has good detail, a high level of musicality but most of all, the most mid body with good bass impact.

The part on Amplification (synergy) and Comparisons can be found on Page Three, after the jump below or the click HERE


Lieven is living in Europe and he's the leader of the gang. He's running Headfonia as a side project next to his full time day job in Digital Marketing & Consultancy. He's a big fan of tube amps and custom inear monitors and has published hundreds of product reviews over the years.


  • Reply July 7, 2017


    Seem to be cool ones! But these seem as an alternative for me Sennheiser M2IEi

  • Reply September 8, 2018


    Great review, thanks!

    You reckon the new CL2 is the same power-hungry and requires a DAP?

    RHA customer support says it can be used without DAP, but doubting that…

  • Reply December 27, 2018



    I have these earphones for over a year. Unfortunately they must be connected to an amplifier in order to be able to play decently. However, the highs are metallic and require equalization. I prefer the sound of the Philips Fidelio X2 headphones. Unfortunately I did not try any other earphones to be able to make a comparison.

  • Reply March 13, 2019


    Excellent review, I love the CL1,s and it is a pity they have been discontinued, I think they should have been more popular than they were, I think because they need a very good amp to really appreciate them, that was there downfall, my favourite has been the LakePeople G109 which drives them to their full potential, I also enjoy them with Ibasso DX100 and DX80 and waiting on the Dacamp L1, I got them for a 3rd of the price new so my gain that I am late to the party and have managed to snag a second set very cheaply as a back up!! Love them!!

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