My last review of an RHA audio product was back in 2013, when RHA was building up their product range. 5 years later, they have grown in strength and reputation, manufacturing in-ear headphones that impressed both audiophiles and consumers alike. Since 2011, their mission has been to advance earphone technology combining elegant, functional design and intuitive features. The RHA CL2 Planar is one of the great outcomes of this mission.
What’s extraordinary about CL2 Planar is that it is the smallest commercial planar magnetic driver ever released. And to top it up, CL2 Planar is also the first closed-back planar magnetic in-ear headphones. The CL2 Planar supports detachable cables to switch from wireless to wired, from unbalanced 3.5mm to balanced 2.5mm audio connector.
It took RHA four years of development to achieve a compact 10mm planar magnetic driver protected inside injection-moulded zirconium dioxide housings that are near-indestructible. Obviously, the package comes at a premium. The RHA CL2 Planar retails for S$1588 in Singapore, distributed by Eng Siang.
Planar Magnetic Drivers
A majority of in-ear headphones uses dynamic drivers, which are made of single magnetic coil in the middle of the diaphragm to generate sound waves. Planar magnetic drivers manipulate the entire surface of the diaphragm using 2 magnetic plates components laid across the diaphragm surface, hence the term “planar magnetic”. The result is often better details, greater signal accuracy and faster audio response.
CL2 Audio Assessment
The CL2 Planar delivers many of the traits of planar magnetic headphones, that is, the bass is usually not heavy nor overpowering, while the overall audio details are exceptional. Thanks to a clean neutral bass that does not cloud the sound, lots of instrumental fabrics are prominent to my ears. CL2 lets me enjoy the bass passages as an proper musical section instead of just for feels. The sound staging is subtly wide and the instrument spacing is apparent which makes normal tracks sound a little more immersive. And with planar magnetic, every musical tone and beat is snappy which gives room for multiple layers to be heard.
One way to determine how good, different, or special a pair of headphones is is to find out whether the headphones let me hear new information that I previously did not pick up. On the CL2 Planar, when I played Hotel California (Live), my ears picked up the background guitar lines over the vocals. Similarly, reverbs take less effort to be heard. Such are the pleasures of listening to planar magnetic headphones.
However, the CL2 tuning does not allow me to wholeheartedly enjoy these expensive earphones. The CL2 has slight emphasis on the mid-treble range, which is around 4000 Hz. The human ear is most sensitive to this frequency range, and I am probably those who gets irritated by this range. It all comes down to the sensitivity of your ears. To be objective, the bloom produced by CL2 is not as excessive and accidental compared to other earphones. It appears the RHA engineers have the intention to push the details around this frequency range, an intentional emphasis of the mid-treble to bring out details. Hence, listening to Earth Wind and Fire’s Boogie Wonderland is an academic process instead of one that will move your feet.
As we all know, the eartips do play a part in altering the sound signature. To counter this characteristics, I find the the double-flange eartips helps in improving my listening comfort. What the double-flange eartips do is to bring up the high treble presence so that the mid-treble harsh is less prominent. Additionally, the bass is also slightly boosted to further improve the enjoyment. The included Comply foam tips do not work for me: the tips come with a thin mesh which further veils the sound production, accentuating the shimmy mid-treble.
I can wrap up my assessment by concluding that the CL2 delivers excellent musical response and balanced tuning throughout the frequency range. No excessive bass, no exaggerated highs, well-portrayed midrange for a neutral-warm sound. The slight emphasis on mid-treble has contributed to additional energy towards the midrange and treble presence.
Overall Usability
The CL2 Planar comes with a generous set of accessories to allow the user to enjoy music in both wired and wireless. The included 3.5mm braided OFC cables and 2.5mm braided silver-coated cables are thick which say a lot about the quality. But I’m not a fan of the rigid cables, especially when the behind-the-ear hook is a little too thick and stiff to keep the cables in place. I have to say that this type of inconvenience is common for thick premium cables.
The wireless neckband has enough battery to listen for 12 hours, and is charged over USB Type-C port which is exposed without a rubber cap, making me worry about durability against moisture. I do not use a lot of MMCX earphones, but the CL2 Planar connectivity is really tight and challenging to remove, making me worry that my excessive force might someday break the cables.
When I do not wear the earbuds, they dangle down, and due to the cable length, they tend to swing around. For a pair of expensive earphones with sensitive planar magnetic drivers, it does not sound like a good idea to keep the CL2 around the neck casually. But if you find that acceptable, the neckband has a vibration motor that alerts incoming calls. Besides, it would be a waste of the planar magnetic drivers if you are going to listen primarily on wireless. Transmitted over aptX, they sound more compressed, more pushy than wired. The highs sound brighter but are less disciplined, lacking in finer info like reverb.
Verdict
There is no doubt the RHA CL2 Planar in-ear headphones are an engineering achievement, allowing audio lovers to enjoy the benefits of planar magnetic drivers. The retail package is comprehensive to cater to both casual listeners and audiophiles. Thanks to technology, expensive speaker drivers are more affordable (relatively-speaking) and more compact for every-day use. The CL2 Planar is easy to drive, plays well on smartphones, but a great DAP will further elevate its potential. The price is not as palatable and the sound profile may not be as easily likable due to the slight emphasis on mid-treble. For similar price point, I find the Beyerdynamic Xelento more enjoyable to listen to, more comfortable to wear. For an alternative planar magnetic headphones, consider Audeze Mobius 3D headphones which delivers more enjoyable clear highs with less harshess (plus the sound localisation effect is really cool).
Likes
- Above-average details, balanced delivery delivered from lows to highs
- Extensive accessories and cable options
Dislike
- Listening joy of planar magnetic overshadowed by emphasis on mid-treble
Accessories
- Braided Ag4x silver coated cable: MMCX – 2.5mm balanced
- Braided oxygen-free copper (OFC) cable: MMCX – 3.5mm
- SecureFlex Bluetooth® neckband: MMCX
- Flight case
- Carry pouch
- Stainless steel ear tip holder
- USB C charging cable
- Flight adapter
- Dual density silicone ear tips: 2xS, 2xM,2xL
- Double flange silicone ear tips: 1xS,1xL
- Comply™ Foam Tsx400 ear tips: 3xM
- Sports clip
Technical Information
- Weight – 9g (housings only)
- Material – Zirconium
- Frequency range – 16Hz – 45,000 Hz (wired connections)
- Driver – Planar Magnetic
- Bluetooth® version – 4.1
- Range – 10m (unobstructed)
- Bluetooth codecs – SBC, AAC, aptX™
- Battery – Lithium polymer rechargeable
- Battery life – 12 hours (60%)
- Charging – USB C: 1.5 hours from 0%
- Remote & mic – 3-button, universal
Pricing & Availability
RHA CL2 Planar is available at a recommended retail price (RRP) of S$1,588 (including GST) at authorized retailers including AV One, Stereo Electronics, Challenger, Popular, Connect IT, SingTel, iStudio, Gadget Plus, Gadget Hub, Motion Sports, XGear, Cumulus Nimbus and Treoo.com.





1 comment
The pushed 1-8 Hz tuning destroys what would other wise be a great set of headphones. Horrible tuning, the worst purchase of headphones I have ever made. I bought them as my Shure KSE1500’s don’t have enough volume for my liking with an A&K SP1000. CL2, great definition but horrible harsh metallic sound and who wants to have to have a preset EQ on their player just to make a S$ 1650 set of headphones usable……Goes to show you have to try them first!