The RHA CL1: RHA’s flagship IEM, and the crown jewel of the CL series. While these are a clear step in the right direction from the CL750, and while I do enjoy these, they feel like they are still a few tweaks away from greatness. The CL1 is RHA’s only multi-driver product, with a standard dynamic driver covering bass, mids, and some treble, and with a unique ceramic plate driver which takes over at 8kHz and above. With an impedance of 150 ohms, and a sensitivity of 89dB, one would think these are hard to power, but that simply is not the case, easily being driven by my iPhone 6s. While these worked off of my iPhone, I used them paired with my SMSL SAP-9 for the vast majority of my listening, and all of my evaluation of the sound is based on this pairing.

Included in the box are two cables, one standard cable, and one mini 4-pin XLR cable for use with RHA’s L1 portable DAC/amp, 6 sizes of standard silicone tips, 2 pairs of double flange tips, 3 pairs of Comply foam tips, a branded shirt clip, a cleaning cloth, a screw-on quarter inch adapter, and a protective carry case. The tips I decided on were the standard silicone tips, as usual, as double-flange tips never fit right for me, and I personally dislike foam tips. The carry case is identical to the one included with the CL750, and while it was fine for those, I would have liked something a little more stiff for something of this price; however, at this price, I would personally go with a Pelican 1010 over just about anything anyways.

The build on the CL1 is quite nice. The housings themselves are made of a glossy black ceramic, and feel extremely solid. The cable, however, is not quite up to par, being identical to the CL750 cable. This cable was acceptable at 140USD, but not so at 450USD being too rubbery and microphonic for this price bracket, though it does feel plenty sturdy. Fortunately, the cable is detachable, however, it is unfortunately detachable with a recessed locking MMCX, which they call sMMCX, and I have not encountered any other cable that reaches the recessed connector.

The fit on these is also quite nice, with the exception of the stiff memory wire on the cable. The housing itself is shaped more like a Shure than the other RHA products I’ve reviewed, and fits nicely in the ear, without putting any pressure on any part of my ear. While the housing has a little bit more weight to it than most, I did not find this to be an issue. The memory wire on the cable is far from ideal, as it will not deform enough to actually wrap neatly, and instead floats vaguely around my ear, which can get quite annoying.

The CL1s have an overall bright tuning, much like the CL750, but unlike the CL750, this is much more well executed, if still needing a little more refinement. The bass rolls off a little bit, but not nearly to the degree of the CL750. Bass notes hit nicely, having a pleasant little bit of thump to them, though it could use a little bit more presence. Bass overall takes a back seat with these IEMs, which instead focus more on the midrange and treble. The midrange is very clean sounding, and sounds quite even throughout. Vocals sound very natural, with plenty of weight and meat to them, while remaining tonally correct. The treble is quite elevated, with an overall upward tilt to the entirety of the treble. The treble sounds quite detailed and resolving, though certainly more so at lower treble frequencies. There seems to be a bit of a dip in the mid treble, which gives this IEM a bit of a more laid-back sound, if some sounds are a bit distant sounding as a result. At the higher treble, the ceramic plate driver takes over, and is even more elevated, perhaps a little too elevated. The soundstage is decently wide, giving the treble plenty of space so it does not sound too in-your-face. Imaging is quite good as well, making good use of the clean treble.

The CL1 is not too sensitive to different tips. With Spinfit tips, the sound did not change significantly, though the fit felt a little off. I was hesitant to even put Spiral Dots on it, as they are known to increase the treble, which they did. The Spiral Dots made the CL1 a tinny mess, ruining everything that makes this IEM good, and also fitting weirdly. Needless to say, I stuck with the stock tips.

Now, I mentioned that the CL1 felt like it was a few tweaks away from greatness, and while I am no engineer, the tweaks I have in mind seem entirely possible. Firstly, regular MMCX or 2-pin would be a huge improvement, as I am not a fan of the stock cable, and would love to use my Pinnacle cable with it. Secondly, I feel a little bit more bass would be an improvement, as the bass can sound a little bit lacking. Thirdly, the higher treble from the ceramic plate driver is a little bit too elevated, as if the ceramic plate driver was a little bit too efficient relative to the dynamic driver. If these three changes were made to the CL1, this would be an outstanding IEM for those looking for a brighter tuning, and I would likely buy one myself. In its current form though, the CL1 is still not a bad deal.

In conclusion, I like the CL1. With a pleasing bright tuning, it is a very nice listen, bringing a nice sparkle to many tracks. While it is not perfect, RHA is certainly on the right track, and a future CL series IEM could be truly spectacular.