- Exceptional audio performance with rich, accurate lows and wonderful high frequency clarity.
- Ships with twelve eartip options in various sizes, shapes, materials.
- Designed to be used with a headphone amp (though it can be plugged directly into many sound sources).
- No inline remote control.
- The RHA CL750 headphones deliver a fantastic in-ear audio experience that gets even better when used with an amplifier.
The CL750’s earpieces feature stainless steel enclosures that house “ultra wideband” dynamic drivers that cover a frequency range of 16Hz-45kHz. The cabling is rather eye-catching, made of oxygen-free copper wire coated in translucent TPE, braided for durability and a dramatic look. The cable terminates in a stainless steel 3.5mm connection.
The in-canal fit is quite secure thanks in part to some stiff cable at the base of each earpiece that can be molded and snaked over the ear. But the primary reason the CL750 fits so well is that RHA throws in a ridiculous assortment of eartips. You get twelve pairs in all, some of them Comply foam tips, others silicone tips in two different shapes and various sizes. We’ve tested plenty of more expensive earphones that ship with only two or three total eartip pairs, to put this number in perspective. There’s even a metallic sheet the eartips snap on to for easy storage inside the included, zip-up canvas protective pouch.
Because the headphones feature a high impedance (150 Ohms), it is recommended that you use them with a headphone amp. As mentioned, the portable Dacamp L1 from RHA helps the CL750 deliver fantastic audio, with adjustable bass and treble, as well as gain levels. You can opt for a less expensive amp, though the headphones can also be used with some mobile devices directly—the only real issue is that you need to operate at much higher volume levels than you typically would in order to get normal decibel levels. In other words, you might nearly max out of the volume on your phone and have a listening level through the CL750 that would be akin to lower volume settings when used with other earphones.
But, at least when used with an iPhone 6s for testing, the CL750 was able to deliver excellent, vibrant audio with no headphone amp. At maximum volume, it was actually too loud for comfortable long-term listening, and at slightly lower levels, the audio was excellent, with vibrant bass response similar to what you’d hear through the Dacamp L1 if all of its bass and treble settings were zeroed out and the gain were set to low. There’s no denying that the $550 Dacamp L1 adds to the audio experience (as would several other portable headphone amps that act as digital-to-analog converters and bypass your mobile device’s typically inferior DAC and headphone jack), but the CL750 can definitely be used without it.
Since we’re not reviewing the Dacamp L1, we’ll just say one last time that it does enhance the audio experience tremendously, but the results below were achieved when connected directly to the headphone jack of an iPhone 6s. Again, the CL750 got plenty loud for us in this scenario, and on tracks with intense sub-bass content, like The Knife’s “Silent Shout,” the headphones deliver accurate, powerful deep lows that are balanced out with superb clarity in the highs. Every click and high frequency percussive sound here is clear and balances well with the powerful bass.
Bill Callahan’s “Drover,” a track with far less deep bass in the mix, gives a better sense of the CL750’s overall sound signature. On this track, the drums get some added bass depth, but nothing too dramatic—they have a pleasant roundness to them. Callahan’s rich baritone vocals receive plenty of treble edge that provides contour and clarity. The guitar strumming and percussive hits also benefit from a strong high frequency presence—there’s definitely a little boosting here, but nothing that creates overly sibilant vocals or a sense of imbalance in the mix. This is a bright, crystal clear sound signature that has richness and bass depth when the mix calls for it.
On Jay-Z and Kanye West’s “No Church in the Wild,” the kick drum loop receives an ideal amount of high-mid presence, giving its attack a sharp presence that slices through the layers of the mix. All of the vocals on this track are delivered with an emphasis on high-mid clarity, as well—you never have sibilance nor harshness, but there’s a bright feel to all of the performances. The sub-bass synth hits that punctuate the beat are delivered with plenty of power, but nothing over the top. If anything feels at all too boosted here, perhaps it’s the highs, which seems to be dialed up a bit—the vinyl crackle and hiss that’s usually relegated to the background is pushed forward in the mix here a bit.
On orchestral tracks, like the opening scene in John Adams’ The Gospel According to the Other Mary, the lower register instrumentation has a pleasant depth to it—things aren’t boosted much in this realm, just slightly, so that the lower bass moments in the mix have a little added vibrance, but nothing that sounds unnatural. The higher register strings, brass, and vocals have an excellent presence through the CL750—there’s ideal high frequency definition that allows the brighter instruments to truly shine in the mix without upsetting the overall balance. Purists may find the lows a tad too boosted and the highs too sculpted, but most listeners will enjoy the clean, clear sound signature.
It feels strange to endorse using a product in a way the manufacturer doesn’t necessarily intend, but the RHA CL750 headphones deliver quality audio with or without an amp. Do they sound better through an amp like the Dacamp L1? Absolutely. But the highs are still crystal clear and the bass is still full and rich without one—all you need to do is to boost the volume. In this general price range, you might also consider the Optoma NuForce HEM2$179.00 at Amazon, the Bowers & Wilkins C5 Series 2$149.98 at Amazon, or the Master & Dynamic ME05$199.00 at Amazon if the CL750 feels too niche for you. And for far less money, the 1More Triple Driver In-Ear$99.99 at Amazon delivers a quality audio experience. The CL750 earn our Editors’ Choice award because they deliver a splendid audio experience at a very reasonable price—and because they have a nice design that includes a plethora or eartip fit options. If you add in that headphone amp, things only get better.