Cleer Flow II Bluetooth ANC headphone review: Exceptional sound quality and excellent noise cancelling

Cleer Audio is a relative newcomer in the headphone market. It was founded in 2012 with a focus on DJ headphones, but that focus changed to consumer products in 2016. Since then, the company has wasted no time; it now offers four in-ear and four over-ear models with more on the way.

The Flow II is one of Cleer’s latest models. It’s a wireless Bluetooth headphone with active noise cancellation (ANC) and compatibility with Google Assistant voice control. Most importantly, the overall sound quality is exceptional.

This review is part of TechHive’s coverage of the best headphones, where you’ll find reviews of competing products, plus a buyer’s guide to the features you should consider when shopping.


The Flow II is an over-ear, closed-back headphone with softly padded earcups and headband. The ovoid earcups are somewhat smaller than most over-ear headphones I’ve tried, making them a bit fiddly to seat properly. It weighs a mere 11.5 ounces, which is lighter than many such headphones, yet its build quality seems quite substantial.

Cleer, Inc.

Cleer says its Ironless Driver design uses rings of rare-earth magnets with no iron to improve the focus of the magnetic field, allowing more voice-coil excursion with lower distortion. The 40mm magnesium diaphragm with polyurethane surround offers low mass, high rigidity, and high internal damping.

Each driver employs a full-range 40mm magnesium diaphragm with polyurethane surround, resulting in low mass, high rigidity, and high internal damping. The magnet structure uses no iron; instead, it is comprised of 20 rare-earth magnets in a ring structure. Cleer calls this Ironless Driver Technology, which is said to improve the focus of the magnetic field, allowing more voice-coil excursion with lower distortion. Specifically, Cleer claims the THD (total harmonic distortion) at 100dB SPL is less than half that of a conventional magnetic driver across the entire audio spectrum and up to six times less in the upper-midrange region.

The specified frequency response extends from 20Hz to 40kHz using a wired connection, garnering Hi-Res Audio certification in that case. With Bluetooth, the frequency response is specified from 20Hz to 20kHz. No tolerance is given in either case.

Speaking of Bluetooth, the Flow II implements version 4.2 with the A2DP 1.3.1, AVRCP 1.6, HFP 1.6, and SPP 1.0 profiles. The supported audio codecs include AAC, aptX, aptX HD, and LDAC. You can pair the headphone with the source device in the usual manner, or—if the device supports NFC (Near-Field Communication) pairing—you can simply hold it near the right earcup and they will pair automatically.

Cleer touts its “hybrid” noise cancellation, which combines passive isolation with active noise cancelling (ANC) for up to 30dB attenuation of wideband ambient noise. The Flow II powers up with ANC on, but of course, you can turn it off, which activates Ambient Mode that lets you hears sounds around you. In this mode, the external microphones pick up ambient sound, which is played in the headphones along with the music you’re listening to.

The only thing I wish for here is a third option that disengages ANC but does not activate the external microphone. That way, you could still have passive isolation and extend the battery life.