Review: Cleer Audio Flow II Wireless ANC – Comfortably and Quietly Carving a Piece of the Pie

Style and substance in equal measure make the Cleer Audio Flow II a clear choice.

First Impressions

The style is much more appealing than the more commonplace black-on-black plastic. The Flow II appears more premium than most, with sharp-looking ear cups and a well-put-together package. Complementing the premium feel are the excellent packaging, travel case, and ample accessories.

While they firmly grip your head and begin to block out noise as soon as you put them on, they are reasonably plush, comfortable, and well-balanced on my head.

Company Overview

Established in 2012, Cleer is a San Diego, CA, United States-based, award-winning manufacturer of high-performance headphones and electronics. Cleer was founded with a shared passion for the ultimate listening experience, and a quest to pioneer the highest standards of audio and realize its potential through both performance and style.

Technical Specifications

• Type: Circumaural (over-ear) hybrid noise-canceling Bluetooth headphones; foldable swivel design
• Transducer driver: 40mm dynamic Ironless Drivers™ (PET + paper) with 20 rare-earth “Radial Magnet Structure” (Cleer proprietary patented engineering)
• Frequency range: 20-40KHz (Line in) / 20-20KHz (Bluetooth)
• Impedance: 16 Ohms
• Sensitivity: Approximately 110dB
• Support: BT 4.2, SPP V1.0, HFP V1.6, A2DP v1.3.1, AVRCP V1.6
• Bluetooth Chipset: Qualcomm CSR 8675
• Bluetooth Audio CODEC support: SBC, AAC, aptX, aptX HD, LDAC
• Bluetooth transmission frequency range: 2.402 – 2.480GHz
• Bluetooth transmission power: <4dBm
• Charging: A 10-minute charge will give 2 hours of playtime; full charge in 2 hours with a 5V1A qualified output adapter or with the computer’s USB interface
• Battery: High-capacity rechargeable polymer lithium-ion rectangle cell (3.7v, 850 mAh)
• Playback time (BT+ANC): 20+ hours playback time continuously with a fully charged battery (with Bluetooth and noise-cancellation activated at 75% volume)
• Microphone: Onboard in ear cup for calls and voice service
• Voice service: Google Assistant
• Connections: USB-C to USB-A cable for charging; 3.5mm to 3.5mm cable for audio
• Cable length and type: 1.2m (4 ft) detachable high-quality black cable
• Plug type: 3.5mm (1/8”) gold-plated straight plug
• Weight (excluding cable): 327g (11.5 oz)

Packaging

Packaging is sturdy outside and in. The outer two-piece stiff cardboard box is nicely designed. Removing the sleeve and opening the black box reveals the tidy hard shell travel/storage case. Opening this case reveals the Flow II headphones, perfectly placed in their protective case. On the outside, there is a mesh pouch on the rear and a pre-installed carry handle/loop strap.

This is one of the best custom-designed cases I’ve come across with some exceptionally thoughtful interior touches. Designed and manufactured for the Flow II, everything fits perfectly and has its place. At the top, there is a small tab with a diagram showing you exactly how to fold the headphones to have them fit properly.

There is a dedicated space for the 2 included cables and the airplane adapter. There are specific soft surface separating tabs to ensure that the cups do not scratch one another, and an included strip of foam which I continue to slide in between the headband and the ear cup. On the left side, there is a secured control reminder card and a mesh pouch.

In the box

• Flow II circumaural (over-ear) wireless hybrid noise-canceling headphones
• USB-C Cable
• 1.2m (4ft) 3.5mm to 3.5mm audio cable
• In-flight adapter for airplanes
• Hard-shell carrying case
• Quick Start Guide

Design

The physical appearance of the Flow II is consumer premium. In this case, looking premium does translate to feeling premium. While there is plenty of plastic, it is cleanly finished and the main pieces are substantial. The headband is solid metal covered in plastic parts, thinly padded with a super-soft liner at the top. I expect the whole package will be highly durable over time.

The fit and finish are immaculate, other than some plastic covering pieces on the headband creaking when flexed when the headband is at its smallest setting. This is not an issue while in use. There are no irritating noises or rattling coming from any part of the headphones while wearing.

The outer rings on the ear cups are beautifully machined and attractive — they catch and reflect light tastefully. The Cleer logo is understated, and the colors nicely matched.

The ear cups rotate and pivot to allow for intentional movement in several directions, adapting well to most people’s heads. The ear pads are plush while not being overly stuffed, maintaining a reasonably slim profile. Weight is enough to feel sturdy, light enough to be comfortable for long wearing periods.

The Flow II’s arms fold for storage to reduce their physical footprint. They are small and likely tough enough to be easily thrown into a bag. That said, these regal headphones politely request that you treat them with respect and care for them as they deserve, by properly placing them in their case. This will most certainly help the Flow II maintain their striking good looks with the little beauty rest you will give them.

Comfort

Clamping pressure is substantial (not enough to cause headaches) and helps ensure a strong seal and passive noise isolation. The high-quality faux leather ear pads are soft, a great balance between firm and plush. They will cover most people’s ears snugly, though will be a tight fit for those with larger ones. Personally, I would prefer a bit more interior room.

Speaking of breathing, these ear pads do not ventilate particularly well. That said, I rarely found them to be too hot unless it was a particularly warm day. Those who are in cooler climates or interior air-conditioned areas will welcome the minor warmth and comfort they provide.

Even with a fixed headband, there is good adjustability with positive actuation and will fit heads both narrow and wide. The shape of the headband around and above the head when wearing is somewhat oddly flat rather than rounded.

If you have a particularly oval/oblong shaped skull, there is a possibility that you may experience a hot spot on the very top of your head. That is roughly the shape of my head, and I have had no significant discomfort. The cushioning of the fixed-shape headband feels comfortable to the touch, though in my opinion is a bit too thin and soft.

The positive is that the modest weight of the Flow II is carried by the grip of the ear cups. After extended listening periods, I find them to be well-balanced and comfortable and do not experience any pressure points.

It is important to note that the ear pads are non-replaceable. From what I experience, this is not going to be an issue for a long time.

Internals

Cleer’s Ironless Driver™ Technology is a radial magnet structure of 20 strategically layered, rare-earth magnets for effective voice coil control and efficient translation of electrical impulse into composed and expressive sound. Rather than using iron, magnesium alloy is the metal of choice.

This technology allows for more fluid and free-flowing diaphragm movement, drastically reducing distortion across all frequencies, particularly in the upper-frequency range.

Flow II Performance & Features

The Flow II are moderately efficient and are adequately driven by most mid to high-quality devices when connected with the auxiliary cable. They can also be powered on to use ANC while wired.

Bluetooth performance

The Flow II use Qualcomm’s CSR8675 chip, which integrates a dual-mode radio and hybrid noise-canceling technology that achieves up to 30 decibels of ambient noise suppression. Pairing the Flow II is simple and fast. Bluetooth connectivity, speed, stability, and range were strong and consistent in all of my testing across all sources.

Active noise-cancellation (ANC)

In earlier days of noise-canceling technology, the negative effects on sound reproduction and quality were painful for enthusiasts and completely unacceptable for audiophiles.

Decent ANC performance came at the expense of good sound, given that they were purpose built to quiet the fairly steady low frequencies made by airplanes, trains, etc., and other environments with high ambient noise, like busy cafes. As a result, ANC was frequently a reasonable excuse for poor sound.

ANC technology has advanced quickly. Cleer has certainly leveraged these gains and, along with other more advanced headphones, worked toward eliminating the original trade offs.

The Flow II are active hybrid noise-canceling headphones with a microphone inside and outside the ear cup. They take constant measurements to quickly cancel the noise. With optimized passive and active isolation, custom filters, and powerful digital signal processing, they suppress wideband ambient noise up to 30dB.

Ever since ANC headphones became widely available for general consumers, many people experience discomfort while using them. Some of the most common symptoms include headaches, dizziness, and nausea. While I find that the Cleer’s hybrid ANC is highly effective, I do not find it overwhelming nor did I experience any disorientation or discomfort.

When enabled, there is low-grade hiss in the quiet spaces from ANC. This virtually disappears and becomes inaudible when music or another audio signal is being transmitted through the drivers.

Putting on the Flow II with ANC mode off, the passive isolation itself is so effective that I still occasionally think that the ANC is enabled. There is a slight vacuum effect putting them on. Even with significant clamp force, the Flow II block a lot of outside noise with the ear pads making a strong seal. Despite this, I never experienced an uncomfortable buildup of pressure in my ears.

Another historical trade-off was that anti-noise sounded more obviously unnatural. With the Flow II, it just works. Not too little or too much. You will not find yourself in a true magical cone of silence; you will find that a large quantity of background noise moves so much further into the background that it is much less distracting. You will not have to crank up the volume to unhealthy levels to compensate for intruding sound.

Touch controls

The controls for the Flow II are fairly easy to learn and remember. There are three physical buttons on the left ear cup: Power/Pairing, Active noise-cancellation (ANC)/Ambient mode, and Google Assistant.

Other features are accessed via touch and swipe controls, also on the left ear cup. You can play/pause tracks and answer/hang up calls with a double-tap, swipe up or down to adjust the volume, and skip tracks by swiping forward and backward. I find them to be responsive, accurate, and useful.

In addition, by simply covering the left earcup with several fingers or your hand, the ambient/conversation mode is enabled, ANC is disabled, and the volume is reduced, allowing you to better hear and interact with the world around you. This is both useful and an important safety feature.

The touch panel does not function when powered down or when the 3.5mm aux cable is plugged in.

Microphone performance

With undisclosed microphone technology, the Flow II performed well, considering this is not a main product feature.

It is perfectly acceptable for professional/business calls taken indoors in relatively quiet environments. There does not appear to be ANC for the onboard microphones used for calls.

Battery performance

Battery life is an impressive 20+ hours playback time continuously with a fully charged battery (with Bluetooth and noise-cancellation activated at 75% volume). The Flow II has a quick charge feature as well – a 10-minute charge will provide an astounding 2 hours of playback.

The Flow II has an automatic audio signal detection function. When the audio signal is not detected for 30 minutes, it is determined that the headphones are not in use, and they will automatically power off to save battery life. In ANC mode, even if the audio signal is not detected for a long time, the headphones will not automatically power off. This is done to support long flights and potential for wearing when asleep.

Remaining battery capacity will be displayed on supporting phones after connecting. If your phone supports this, there will be a battery graphic in the notification bar of the mobile phone, and the remaining power will be displayed in a graphic form. When the Flow II battery is less than 10%, there will be a “low battery” voice prompt.

Additional features

There is one indicator light (consult the manual) to show the status of the headphone. The Flow II will support two connected devices, making multi-switching easy.

For those who are familiar with or live in the Google ecosystem, this will delight you! There is a dedicated button to access Google Assistant (not available in China).

For me, one of the greatest features is quite understated: when you take the headphones off, whatever you are listening to, including online and offline videos, will automatically pause. Even better, they will auto-resume when you put the headphones back on! This is also true for phone calls, as music is automatically paused when a call is received or made. When you hang up, music will resume playing automatically.

Cleer Flow II Sound

For evaluation, I listen to a great variety of music through numerous sources, including:

• Sony DVP-S7000 CD Player
• LG V20 phone with quad DAC (has a headphone jack)
• Samsung A71 (in 2020-21, still has a headphone jack!)
• iPhone 7 Plus
• Samsung Chromebook
• FiiO A3
• Khadas Tone2 Pro

First things first: is there a difference between the Bluetooth and wired connections in the Flow II? There is a slight difference when connected to a high-quality amplified source. To be clear, it’s not that either is lacking or one is much better – it improves from very good to excellent. Straight away, they do not need equalization to alter the tuning.

It sounds to me that Cleer tuned the Flow II while adjusting for the full effects of ANC and BT. Many manufacturers have made noise-canceling products that seem to have been tuned using an opposite process, tuning the headphones and then applying the ANC as a feature, with unimpressive results. I am surprised that the ANC does not negatively affect or interfere with overall sound quality.

Cleer asserts that the Flow II’s performance “…will impress your inner audiophile” — I agree!

The Flow II have a non-fatiguing, engaging, and warm sound signature. I do not experience the sound reproduction as veiled or dull, nor overly boosted to compensate. Even better for a consumer oriented product, bass is notably present without overemphasis, bloating, or excessive bleed. I’m impressed!

Treble clarity and midrange presence are both impressive and well-balanced. Even at high volume (louder than I can safely listen to) I notice no obvious distortion.

Despite being closed-back headphones with strong ANC, the Flow II demonstrate better than expected soundstage – they do not sound claustrophobic or too “in my head.”

Far better than expected was the excellent imaging, as best demonstrated while watching the 2017 Justice League movie. I was taken aback by how much dimension and imaging was present, while dialogue was still crystal clear. What really blew me away – I was watching on a relatively low quality airplane AV system cruising at 30,000 feet at the time.

Despite having essentially the same driver as the lesser Cleer Enduro, the tuning is very different. While the Enduro has overly emphasized bass, the Flow II sound far more balanced, sophisticated, and mature — highly flexible for music lovers with eclectic taste.

Dynamic range is above average, notable with San Francisco’s Kronos Quartet’s Cage: Totem Ancestor. There are significant changes in loudness, intensity, forwardness, and texture. The notable high frequencies come alongside textured and natural-sounding bass strings without excessive sharpness.

Bass

Overall, these are not bass-head headphones. Bass extends deeply while always under control, relatively fast and taut. The bass is very well tuned, accurate, and very well integrated. Heavy bass does not diminish higher frequencies and clarity.

We begin our musical journey in Poland. Stimulation (Part Three) by Aural Planet is super stressful for headphones. The simultaneous range of electronic sound and noise and deep frequencies will easily cause heavy, unpleasant distortion. While other headphones may provide more physical thump, the Flow II were composed and managed to restrain and refine the distortion. Their track Gene reveals texture.

Midrange

There is so much to subtly appreciate here. Contrasted with so many other mid-range consumer headphones, the midrange sounds balanced and present in the mix. Next stop, let’s visit with Chlara in her home country of the Philippines. Her 2018 single You Really Shouldn’t Have is beautifully presented and smooth. The music and her voice layered in are just beautifully engaging.

Treble

In the same vein, treble is distinct and balanced; I have yet to experience sibilance or any excessive unpleasant sharpness. Clarity and detail present well and remain relatively unaffected by the prominent bass and lower midrange. The GR1 are not shiny or sparkly in treble presentation. They are clear and open – fatigue is a non-issue.

Our last destination for today is Venezuela to hear symphonic heavy metal band Nota Profana, with soprano Gaby Koss from Germany. Dragon’s Grail highlights Gaby’s operatic voice after the 2:00 minute mark. This is complex composition, with fast transitions and extensive treble in her voice, cymbals, and other hammered instruments. There is distinct separation and detail with no sibilance.

If you’d like to hear Gaby’s voice in a more gentle and revealing recording, enjoy her gentle version of the traditional Irish She Moved Through the Fair.

Where to Buy

Thank you once again to Cleer for providing the Flow II for review. If you’d like to purchase a pair, you can buy them directly from Cleer.

Conclusion

The Cleer Flow II headphones stand out in a positive and stylish way. They are high-performers in every area Cleer intended them to be. They make a compelling argument that anyone seeking premium, well-tuned sound can also have ANC as a legitimate bonus — the opposite is true as well.

Given their value for performance, they are highly competitive, an excellent choice, and an absolute bargain at any price below USD$250. If you’ve had a prior negative perception of ANC technology, give these a listen – you’ll be pleasantly surprised by what you do hear, and what you don’t.