Review: RHA CL1 – Specific

Disclaimer: The RHA CL1 universal IEM was sent to us free of charge by RHA months ago, the sample doesn’t need to be returned.



RHA over the last few years really have become an established value in personal audio. Their product range has IEMs in all price ranges and they just keep getting better all the time. For those who have been living on another planet for the last few years, here’s a short resume: RHA is a specialist British audio company and RHA stands short for Reid and Heath Acoustics. It’s actually a Scottish company and it was founded in 2011. RHA stand for true-to-life audio reproduction and lasting quality.

The creator of a unique range of high specification audio products driven by passion and pride. With these values at our core, we work to deliver the most accurate, comfortable and unobtrusive listening experience possible. Every RHA product combines high quality materials, precision engineering and our fundamental commitment to design.

My personal favorite RHA earphone is the T20 although the T10 is very close to that one. RHA with the launch of the DacAmp L1 is no longer only making earphones and they have a portable Dacamp L1 in their lineup now too. Other RHA products we’ve looked at in the past are the T10, T20, MA600 and MA750. RHA also just launched the wireless versions of the MA-series at High End in Munich and I have to say these sounded really good!


The Dacamp L1 was developed and released at the same time as the CL1 IEM we’re looking at today. The CL1 is a harder to drive IEM and therefor RHA designed a portable DAC and amplifier to go with it. We’ve already looked at the L1 a few months ago, so if you haven’t read that review yet I suggest to do that first, right HERE.

It’s important to know that the L1 has a balanced mini-xlr output specifically built for using the RHA CL1 with the balanced cable.

CL1 Ceramic

Like all other RHA earphones, the new CL1 looks gorgeous. Technology wise it also is something unique as RHA chose to implement a dual transducer configuration.

This configuration combines the precision CL Dynamic and dedicated high frequency ceramic plate driver for true-to-life sound. With a crossover configured at 8kHz, the ceramic plate driver controls high frequencies whilst the CL Dynamic transducer delivers unprecedented accuracy in bass and midrange frequencies.

As said, the RHA CL1 is designed for use with headphone amplifiers or high powered DAPs and smartphones. The CL1 features a detachable cable system using custom (unfortunately), locking sMMCX connections for contact efficiency and durability.

The CL1 Ceramic is supplied with two cables. The Ag4x cable uses silver, a highly conductive metal, and is fully balanced; each channel, left and right, positive and negative, stays entirely separate from the the source device to transducer housings. This cable terminates in a 4-pin Mini XLR connection designed for use with the Dacamp L1. The high purity OFC cable is also channel separated to eliminate risk of cross channel interference, and features both 3.5mm and 6.35mm terminations for use with a wide range of audio equipment.

The RHA CL1 also received the Hi-Res Audio label, should that be of any interest to you.

Build Quality & Comfort

As usual from RHA, the CL1 comes in a beautifully finished top quality box and the CL1, just like the T10 and T20, is injection molded. The ceramic black finish makes the CL1 incredibly beautiful. The housings of the CL1 are created using a complex seven stage process. According to RHA, it results in a striking, extremely durable in-ear headphone with low acoustic chamber resonance, eliminating distortion. But it’s not just the sound, the CL1 is absolutely stunning with that shiny black finish.

Size wise the RHA CL1, just like the T10 and T20, is pretty small and the shape easily and comfortably fits your ears. Comfort- and sound wise I prefer the supplied Comply Foam tips. When inserted correctly the CL1 sits very comfortably and the isolation also is very good for a universal IEM. The CL1 is an earphone that you wear over your ears and to do so RHA uses these sublime mouldable hooks which help you keep the inear in place. RHA doesn’t use the standard metal wire solution or heat shrunk plastic to do so, but they use a spring like design where you can really shape the spring to perfectly loop over your ear. It’s perfect and it will fit anyone.

Both of the supplied cables are also very well built and these obviously aren’t the typical cheap, standard, Chinese cables some other companies use. They feel great and look great. The see-through plastic clearly shows the difference between the materials of the balanced and the unbalanced cable.

So basically RHA nailed it again with the CL1 for what packaging, build quality and comfort is concerned. And on top of that they even give you a 3 year warranty. Does it get any better?

Click HERE to go to page two of the review for Amplification and Sound

4.6/5 - (174 votes)

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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