The Clear Mg sits in the middle of Focal’s open-back range: a clear step up from the Hadenys, and the most affordable route to Focal’s top-tier open-back sound below the Utopia. Its 40mm “M”-shaped dome is made of pure magnesium, chosen over the aluminium/magnesium alloy of the original Clear because it is lighter and better damped, which Focal says took four years to develop. Behind it, an inner grille follows the M profile of the dome, and the outer honeycomb grille keeps the design fully open. At 55 ohms and 104dB/mW it is easy to drive, but it rewards a quality amplifier, and Focal supplies both a single-ended and a balanced cable. It is a headphone for listening at home in a quiet room. What it offers is detailed, dynamic and natural open-back sound at a level close to Focal’s best.

Brief product overview

A circumaural open-back headphone with 40mm drivers using a pure magnesium “M”-shaped dome. Magnesium is light and naturally well damped, so the dome responds quickly without ringing. The inner grille is shaped to follow the dome closely for precise high-frequency reproduction, and the large honeycomb outer grille lets the driver breathe freely. Frequency response is quoted at 5Hz to 28kHz, impedance is 55 ohms, sensitivity is 104dB SPL at 1mW, and distortion is 0.25% at 100dB. The earpads and headband are covered in perforated microfibre for comfort over long sessions, and the headphone weighs 450g. Each earcup has its own 3.5mm socket. Supplied are a 1.2m cable with a 3.5mm plug, a 3m balanced cable with a 4-pin XLR, a 6.35mm adapter and a carrying case. It is made in France.

How it sounds

The Clear Mg is detailed, dynamic and natural, with a neutral, well-balanced tonality. Transients are quick and clean, so percussion and plucked strings have real snap, while voices sound full and unforced. The bass is tight and well articulated with genuine depth for an open-back, and the treble is extended and finely resolved without glare. The open design gives a spacious, speaker-like soundstage, considerably more open than any closed-back. The limits are honest ones. As an open-back, it leaks sound and lets outside noise in, so it suits a quiet room, not an office or travel. It is revealing, so the quality of the source and amplifier is clearly heard. And while the Utopia’s beryllium driver goes further in resolution and ease, the Clear Mg gets surprisingly close for considerably less.

What we’d partner it with

For transportable listening, the iFi iDSD Diablo-X is a powerful partner. It is a battery-powered DAC and headphone amplifier with two Burr-Brown DAC chips and a 16-core XMOS processor, handling PCM to 768kHz, DSD512 and MQA, from a USB input for a phone, tablet or laptop or a coaxial/optical S/PDIF input. Its headphone outputs are a 6.35mm single-ended socket, rated at 2.4 watts into 32 ohms, and a 4.4mm balanced socket rated at nearly 5 watts into 32 ohms. Power modes (Normal, Turbo and xMEMS) match its output to the headphone. With the Clear Mg’s single-ended cable it plays through the 6.35mm output, with power to spare in Normal mode. It comes with a travel case, cables and adapters. Two on-list alternatives, stock permitting: the Astell&Kern PD10, a premium digital audio player with built-in streaming and storage, and the iFi GO bar Kensei, a pocket USB DAC/amp for a lighter setup.

For listening at home, the SPL Phonitor SE brings studio-grade amplification from SPL in Germany. Its VOLTAiR technology runs the amplifier from 120-volt rails, far higher than typical headphone amplifiers, giving exceptional headroom and dynamic range, with output of up to 2.7 watts into 600 ohms. It also has SPL’s Phonitor Matrix, a switchable crossfeed with two presets that blends the channels the way the ears hear speakers, which reduces the hard left-right separation of headphone listening. With the optional DAC768xs module fitted, it takes USB, coaxial and optical digital inputs alongside its RCA analogue input. Alternatives, stock permitting, are the SPL Phonitor xe, a step up with balanced outputs and fuller Matrix controls, and the Naim Uniti Atom Headphone Edition, a streaming headphone amplifier.

On cabling, a 4.4mm balanced headphone cable lets the Clear Mg use the Diablo-X’s balanced output; AudioQuest and Chord are the cable brands we stock for the system’s USB and digital connections.

Who shouldn’t buy it

If you need isolation for an office, shared room or travel, the closed-back Stellia gives Focal’s top-tier sound in a sealed design. If you want Focal’s open-back sound for considerably less, the Hadenys uses an aluminium/magnesium driver at an entry-level price. And if you want the most resolution and ease Focal can offer in an open-back, the Utopia’s beryllium driver is the step up.

The Clear Mg’s cables connect to a socket on each earcup; push both plugs fully home. Focal advises a running-in period before the drivers reach their best, so give them some hours of normal listening. Adjust the headband so the earcups sit evenly; the microfibre pads stay cool over long sessions. Start any source at low volume and turn up gradually. With the iDSD Diablo-X, fit the 6.35mm adapter to the 1.2m cable, use the 6.35mm output, and leave the power mode on Normal rather than Turbo. With the Phonitor SE, use the same cable and adapter in its 6.35mm output, and try the two Phonitor Matrix crossfeed presets against the bypass setting to hear which you prefer. The 3m XLR cable is for amplifiers with a 4-pin XLR balanced output and isn’t used with either system as specified. Remember that an open-back headphone is audible to anyone close by. Store it in its case when not in use.