RHA has built a reputation for producing high-quality, high-value personal audio products backed by one of the best warranties in the business. If you've been a regular reader of HomeTheaterReview.com, you may have read Steven Stone's review of the RHA T20 or my review of the RHA MA750 Wireless. At CES 2019, RHA was showing its new flagship CL2 Planar in-ear monitors (IEMs), a planar magnetic design with the audiophile listener in mind. I'm a fan of planar magnetic headphones, but the technology has primarily been used in full-size headphones to this point. This is the first time I've seen planar magnetic driver technology utilized in a sealed form factor this small that also offers a Bluetooth option for use on the go in addition to two wired options.
The Audeze iSine series, by contrast, is an IEM using planar magnetic transducers in a semi-open design, limiting its usefulness to quiet environments. The CL2 not only provides a Bluetooth cable, it also provides very good passive noise isolation, extending its usefulness in noisier environments.
Under development for four years, the CL2 Planar represents a crowning achievement of sorts for Head of Product Design Kyle Hutchison and his team. At $899.95, though, the CL2 Planar is certainly not inexpensive. Can an in-ear monitor at that price also be considered a good value? After all, there are certainly many less expensive options. After a quick listen at CES, I was interested in discovering the answer to that question. But it would require a more comprehensive evaluation. A few weeks later, RHA kindly obliged with a review sample so I could do just that.
The packaging of the CL2 Planar is certainly indicative of a high-end product. There is a heavy slipcase surrounding a box that's reminiscent of origami, unfolding multiple times to reveal the IEM housings, three connector cable options, a hard travel case for carrying all the cables and accessories, a smaller weatherproof zippered soft pouch just large enough to carry just the IEMs with the cable of your choice, a USB C charging cable, airplane adapter, sport clip, and a stainless steel eartip holder loaded with eartip options.
Included are dual density silicone ear tips (2xS, 2xM, 2xL), double flange silicone ear tips (1xS, 1xL), and Comply Foam Tsx400 ear tips (3xM). The IEM housings are made of injection molded zirconium oxide ceramic in a highly polished black, with the RHA name subtly embossed on the outer side and the CL2 model name along with an R or L on the inner side of the housing. Zirconium is both extremely durable (think synthetic diamonds) and lightweight, resulting in the housings weighing nine grams each.
There are lighter IEM housings (think plastic), but the CL2 Planars are light enough that weight never became an issue even during listening sessions of several hours. The three included cable options have Universal MMCX connectors and moldable ear hooks. That means you could opt to connect a different MMCX cable of your choosing, or you could use any of the included cables with other brands of IEM housings with MMCX connectors. That's a definite plus for those that like to experiment with different combinations. The provided cables include a braided oxygen-free copper cable with a 3.5 mm connector, a braided silver-coated cable with a balanced 2.5 mm connector, and a modified version of RHA's SecureFlex 12-hour Bluetooth 4.1 neckband cable with 3-button universal remote and microphone, finished in black anodized stainless steel and compatible with aptX and AAC streaming. The CL2 Planar's impedance rating of 15 ohms and sensitivity of 89 dB make them easy enough to drive.
While I listened extensively with the CL2 Planars connected directly to an Apple iPhone 6 Plus, for critical listening I used the RHA CL2 Planar IEMs connected to the iPhone via an Audioquest DragonFly Red USB DAC/Amp or connected to an Astell & Kern AK240 digital audio player (DAP) as music sources. After trying the different ear tip options, I quickly settled on the Comply tips, because they offered me the best passive isolation and most comfortable fit. For comparison, I used both the Westone W60 Universal fit IEMs ($999.99) and the Ultimate Ears Reference Remastered custom IEMs ($999.99).
With "Someone You Loved" (Tidal, 16 bit/44.1 kHz), from Lewis Capaldi's debut album Divinely Uninspired To A Hellish Extent (Vertigo Berlin), the Scottish singer-songwriter's ballad starts off with a simple piano melody that is soon joined by his emotional vocal. Keeping in mind that the track is by no means an audiophile recording, the piano intro sounded most natural through the CL2 Planars. By comparison to the RHA CL2 Planars, through the Westone W60s the piano sounded distinctly veiled, almost as if I was sitting in the next room listening to it being played through an open door. Through the UE Reference Remastered CIEMs the piano was much closer in sound to the CL2 Planars, although it still sounded very slightly veiled in comparison. The UE Reference Remastered CIEMs have been my reference IEMs for several years. And while not by a lot, the Universal fit RHA CL2 Planars were besting them!
In order to check soundstaging, I queued up the iconic "Billie Jean" (Qobuz, 24 bit/88.2 kHz) from Michael Jackson's Thriller album (Epic Records). This layered track has Michael's background vocals and synthesizer sound effects emanating from the sidewalls, while his lead vocal is anchored center front, drums center rear, and bass and rhythm guitar flanking Michael's lead vocal when listening to a properly set up high-end two-channel system. Through the RHA CL2 Planars, the separation of instruments and voices was quite distinct, with plenty of space between each. The soundstage was impressively wide, much wider than I would have expected from an IEM. The soundstage was also three dimensional, exhibiting some depth, as well as impressive width.
The RHA CL2 Planars don't just shine with pop music, either. I streamed "Fanfare for the Common Man" (Qobuz, 16 Bit / 44.1 kHz) from the album Aaron Copland: Fanfare for the Common Man - Appalachian Spring - Symphony No. 3 (Reference Recordings) performed by the Minnesota Orchestra and conducted by Eiji Oue.
This well-recorded classical track is a favorite of mine for evaluating bass performance. From the opening notes of the kettledrums and gong from the Minnesota Orchestra, I was blown away with how low the RHA CL2 Planars were capable of playing. All of the depth and impact of this great piece of music were present. The shimmering decay of the gong combined with the introduction of the brass instruments to provide all of the majesty this music is known for. RHA states a frequency range of 16 Hz to 45,000 Hz in the specification sheet for the CL2 Planar and I believe them after listening to the Copland piece.
Comparison & Competition
There are many competitors at or near the price point of the RHA CL2 Planar. As mentioned previously, the two that I compared the CL2 to include the Ultimate Ears Reference Remastered custom fit IEMs and the Westone W60 universal fit IEMs (reviewed here). The Weston W60 consistently presented a darker sound signature, especially in the upper frequency range. The UE Reference Remastered was much closer to the balanced sound signature of the CL2 Planar, although it was still a bit veiled sounding in the upper frequency range and produced slightly less bass at the lower end when compared to the CL2 Planar.
The RHA CL2 Planar delivers an accurate, detailed, and tonally rich sound that is downright captivating. The 10 mm planar magnetic transducers deliver the most natural, balanced, and accurate presentation I've heard from an IEM anywhere near its price. The RHA CL2 Planar teases out layers of detail from complicated tracks and presents them in a very coherent, musical way without ever sounding harsh or bright. The soundstage is accurately portrayed and quite wide for an IEM. And there are enough cables, accessories and fit options provided to satisfy almost any discriminating listener shopping for reference level IEMs.
I found the CL2 Planar to be extremely comfortable, even through long listening sessions. Can IEMs at this price point be considered a great value? In my opinion, they can if they're the RHA CL2 Planar. The UE Reference Remastered IEMs have ruled as my reference IEMs for years, but the RHA CL2 Planar has now taken over that top spot.
The combination of their comfortable fit, audiophile grade performance, cable options, and wireless capability means the RHA CL2 Planar satisfies many use cases, making them a very good value in reference IEMs. For those seriously shopping for IEMs in this price range, I recommend you seek out an opportunity to audition the RHA CL2 Planar. But be forewarned: Bring your credit card, because it's likely you won't want to leave without them.