Cleer Audio Next

Thanks to their innovative driver technology, these audiophile cans could prove a valuable tool in the studio.

California‑founded Cleer Audio are relative newcomers to the market, but their headphones have already made an impression, giving some established brands reason to raise an eyebrow. While the Cleer Audio Next passive, open‑backed headphones are primarily aimed at the high‑end ‘audiophile’ market, they incorporate some impressive driver technology and come with performance claims that, if realised, should suit them to headphone‑based mixing. But before I go further, a wallet warning: Cleer Next headphones are not inexpensive.

The Next headphones present a very high‑quality, precision‑engineered look and feel, combining finely finished aluminium die‑cast structural components with lambs’ leather‑covered memory‑foam earpads and headband. The look and feel of the headphones, created by design consultancy BMW Designworks, says ‘sports car interior’ to my eyes, but Cleer themselves talk of wanting to evoke the feel of a fine timepiece. Judging by the kind of watches worn by well‑heeled visitors to high‑end hi‑fi shows, they’re along the right lines.

Elegant machined LEMO plugs and sockets connect the headphone cables to each earcup, and the cable itself looks like it means business and will outlive us all. The only slightly disappointing element from a pro point of view is that the headphone cable is terminated by a 3.5mm jack plug, so the supplied push‑fit adaptor is needed for 6.3mm jack sockets. I’d much prefer it to be the other way around, so that 3.5mm jack use requires an adaptor, or at least that the adaptor be a screw‑on type.

Out With The Iron

So the Cleer Next headphones are a bit bling (there, I’ve said it); and bling isn’t, to my way of thinking, quite the right kind of vibe for a professional audio tool. Stay with me, though, because the Next headphones are equipped internally with a driver that, in completely eschewing iron‑based materials in its motor system, is technically very interesting. Traditionally, headphone (and speaker) drivers employ steel (steel is an alloy of iron and carbon) components to focus magnetic flux into the gap through which the voice coil moves. A problem with this architecture is that steel is both magnetically and electrically conductive and, due to the latter of those qualities, movement of the voice coil generates eddy currents in the steel components that interfere with the input signal. All manner of distortion and compression phenomena can then result. There are, of course, a number of engineering strategies that can be used to minimise eddy current issues, but the solution employed for the Next headphone drivers deletes iron components entirely from the motor system. Instead, an array of 20 small rare‑earth magnets is used to focus the flux around the voice coil. This technique ought to result in significant benefits in terms of reduced distortion. Beyond the technology of the motor system, the Next headphones employ a 40mm pure‑magnesium diaphragm suspended by a polyurethane surround. The combination, say Cleer, results in an optimal combination of rigidity and damping.

There’s more to a pair of headphones than an innovative driver — comfort, for one thing. With their generous, deep, and pillow‑soft memory foam and leather earpads, the Next headphones feel like the epitome of comfort and luxury. Their headband is set up to produce a relatively low clamping force, too, so there’s a reduced feeling of being locked in a vice. But at 455g (including cable) the Next headphones are pretty weighty. To put that weight in some kind of context, the Sennheiser HD400 Pro and Beyerdynamic DT900 Pro X I have lying around weigh in at 281g and 408g respectively.

As well as weighing the Cleer Next headphones, I used some measuring kit to check their impedance, and FuzzMeasure (along with a Neumann KU100 binaural head) to investigate some of their acoustic characteristics. Use of a binaural head for headphone frequency response measurements doesn’t result in definitive data (because it ‘prints’ a simulated ear transfer function on the data), but it does, I think, allow some general comparisons to be made. Diagram 1 shows the binaural head frequency response curves of the Cleer Next compared to the Beyerdynamic DT900 Pro X and Sennheiser HD400 Pro. The first thing to note is that the Next headphones sit roughly in the middle in terms of overall sensitivity, which is fine. Secondly, the Next headphone frequency response shape suggests a slightly scooped overall balance, with some emphasis in the 2‑5 kHz band. Some of the discontinuities that all three headphones display above around 5kHz are down to the quirks of the binaural head (in particular the dip around 7‑10 kHz), but the comparison suggests that, generally, the Next headphones are likely to be brighter than either the Beyerdynamic or Sennheiser models.

Diagram 1: Comparing the frequency responses of the Cleer Next (red trace), Beyerdynamic DT 900 Pro X (blue) and Sennheiser HD400 Pro (green).

Diagram 2 shows the Next headphone impedance curve, and it confirms the published spec of 16Ω. The impedance curve is notable for showing very little sign of the bump that would identify the driver’s low‑frequency fundamental resonance, so this is clearly very well damped. A 16Ω impedance, while a perfectly reasonable load for most interface headphone outputs or dedicated headphone amps, is on the low side for mobile devices. I’d be a bit wary of driving the Cleer Next from an ancient iPhone headphone output, for example, and expecting much level or assuming consistent tonal accuracy.

Diagram 2: The Cleer Next’s measured impedance.

In Use

And so to wearing and listening to the Cleer Next headphones. First impressions of the former are of good comfort with soft yet cool‑to‑the‑touch earpads, and more than adequate internal ear space. I also didn’t find the Cleer Next caused problems with the arms of my glasses; the relatively low clamping force means that they weren’t pressed into the side of my head. The weight is noticeable, but even when I listened to the headphones for an extended period, it didn’t become a particular issue. Your mileage may vary on this. And despite being described as open‑back, the Next headphones do significantly attenuate external noise. In those terms I’d put the Cleer Next nearer a ‘semi‑open’ category.

First listening impressions were of impressive clarity, detail and openness combined with a great sense of bandwidth extension and authority at low frequencies.

First listening impressions were of impressive clarity, detail and openness combined with a great sense of bandwidth extension and authority at low frequencies. If bass is the foundation on which music is built, then the Next headphones have that aspect covered. The high‑frequency end of the Next headphones is similarly satisfying, exhibiting finesse and precision without undue prominence. My suspicion that the Cleer Next would demonstrate some upper‑mid emphasis was borne out subjectively. Acoustic guitars and female vocals, for example, show a noticeable degree of upper harmonic emphasis, and I think an element of the Next headphones’ ability to lay bare the layers and details of a mix derives from this tonal characteristic. That’s not to say that the Next headphones are simply voiced to sound detailed; they also, I think, have a fundamental ability to mine deeply into the midrange and high‑frequency bands to reveal what a mix is truly made of and how it is put together. In fact, a quick experiment with a little EQ to drop the 2kHz to 5kHz band by a couple of dB showed exactly that; the tonal emphasis was reduced, and those acoustic guitars and female vocals regained a more natural balance, yet the useful clarity and detail substantially remained. My feeling is that the benefits of the iron‑free driver may well play a part in their effective midrange performance, and if they were to be used for mix work, the tonal character could be learned and accommodated — it’s not as if such a notion is unheard of in the nearfield monitor world.

The Cleer Next headphones are not inexpensive. However, in a monitoring context, and in comparison to even entry‑level nearfield monitors, they’re decidedly affordable, and the level of quality, of both manufacturing and subjective performance, is well above the average.