Audio T Verdict
The Focal Bathys MG takes the original Bathys idea and pushes it further towards Focal's traditional high-end headphone territory. It remains a genuinely practical wireless headphone with active noise cancellation, Bluetooth, phone-call support and long battery life, but the most important change sits inside the earcups: Focal's 40mm pure-magnesium M-dome drivers.
Those drivers are manufactured in Focal's French workshops and replace the aluminium/magnesium units used by the standard Bathys. The MG designation therefore means rather more than a cosmetic update.
Bluetooth 5.2 Multipoint provides everyday wireless convenience, with AAC, SBC, aptX and aptX Adaptive codec support. If you want to move beyond Bluetooth compression, switch to USB-DAC mode and the Bathys MG can accept PCM audio up to 24-bit/192kHz directly from a compatible computer, phone or tablet.
Focal also gives you three ways of dealing with outside noise. Silent mode provides the strongest active noise reduction, Soft reduces noise more gently for less demanding environments, and Transparent lets more of the outside world through without removing the headphones.
Battery life is strong too. Focal specifies up to 30 hours with Bluetooth and noise cancelling, 35 hours using the analogue jack connection and 42 hours in USB-DAC mode. A 15-minute fast charge provides approximately five additional hours of listening.
Importantly, however, Bathys MG is an active headphone in every mode. Even the 3.5mm analogue input passes through the headphone's internal electronics and requires battery power. If the battery is completely flat, plugging in the analogue cable will not turn Bathys MG into a passive headphone.
Add the Focal and Naim app, personalised Mimi Hearing profile, five-band EQ, eight microphones, voice-assistant support, multipoint pairing and a proper carrying case and the Bathys MG becomes a particularly complete proposition for someone who wants serious headphone sound without giving up the conveniences that make wireless headphones useful in the first place.
Focal Bathys MG Wireless Noise Cancelling Headphones
Bathys MG is Focal's premium Bluetooth closed-back headphone with active noise cancellation, built-in amplification and an integrated high-resolution USB DAC.
Key features include:
- Closed-back over-ear wireless headphones
- Active noise cancellation
- 40mm pure-magnesium M-dome drivers
- Drivers manufactured in Focal's French workshops
- 10Hz–22kHz ±3dB frequency response
- Less than 0.2% harmonic distortion at 1kHz
- Bluetooth 5.2
- Bluetooth Multipoint
- AAC codec
- SBC codec
- aptX codec
- aptX Adaptive codec
- Up to 15m Bluetooth range in suitable conditions
- USB-DAC playback up to 24-bit/192kHz
- 3.5mm analogue wired mode
- Silent ANC mode
- Soft ANC mode
- Transparent mode
- Eight microphones
- Focal and Naim app control
- Mimi Hearing personalisation
- Five-band equaliser
- Voice-assistant support
- 30-hour Bluetooth and ANC battery life
- 35-hour analogue jack battery life
- 42-hour USB-DAC battery life
- Fast charging
- 1060mAh lithium-ion battery
- Approximately 1.5-hour full charging time
- Genuine leather headband
- Ergonomic foam earpads
- Aluminium and magnesium yoke construction
- 350g weight
- Backlit Focal logos
- Carrying case included
What Does MG Mean?
MG refers to the magnesium drivers used inside Bathys MG.
Each earcup contains a 40mm full-range electrodynamic driver whose M-shaped dome is made from magnesium.
40mm Pure-Magnesium M-Dome Drivers
Focal uses magnesium because it combines low mass with a high damping factor.
For a headphone driver, those characteristics help the moving diaphragm respond quickly while controlling unwanted mechanical behaviour.
The M-shaped profile also contributes to the driver's rigidity and forms part of Focal's established headphone engineering.
Made in Focal's French Workshops
The Bathys MG drivers are manufactured by Focal in France.
That puts the acoustic heart of Bathys MG much closer to Focal's specialist wired headphone ranges than a conventional consumer Bluetooth headphone using an externally sourced generic driver.
M-Shaped Inner Grilles
Focal also shapes the inner grilles of the earcups to follow the profile of the drivers.
The intention is to minimise unnecessary obstruction close to the diaphragm and maintain controlled high-frequency reproduction.
10Hz to 22kHz Frequency Response
Focal specifies:
10Hz – 22kHz ±3dB.
The ±3dB qualification makes this more informative than an extreme-frequency figure without a tolerance.
Less Than 0.2% Harmonic Distortion
Focal publishes harmonic distortion of:
Less than 0.2% at 1kHz.
Bluetooth 5.2 Multipoint
Bathys MG uses Bluetooth 5.2 with Multipoint connectivity.
Multipoint allows the headphones to remain connected to two compatible devices at the same time, with audio switching between them when required.
A typical example would be listening from a laptop while remaining connected to a smartphone for calls.
Up to Eight Remembered Bluetooth Devices
Focal allows up to eight devices to be stored in the headphone's Bluetooth pairing list.
Two can remain connected simultaneously through Multipoint, although only one provides the active audio stream at a time.
Bluetooth Codecs
Supported Bluetooth codecs include:
- SBC
- AAC
- aptX
- aptX Adaptive
aptX Adaptive
aptX Adaptive is available when the transmitting device also supports it.
It provides a higher-performance Bluetooth option and can also reduce latency compared with basic Bluetooth audio, making it useful for compatible video and gaming applications.
Bluetooth Codec Depends on Your Source
The headphones and transmitting device must support the same codec.
If your phone does not support aptX Adaptive, Bathys MG will automatically use another compatible Bluetooth codec such as AAC, aptX or SBC.
Bluetooth Range
Focal specifies a maximum Bluetooth range of approximately:
15 metres in suitable unobstructed conditions.
Walls, furniture, other wireless equipment and the transmitting device itself can reduce the practical range.
Active Noise Cancellation
Bathys MG uses microphones around the earcups to analyse surrounding noise and generate an opposing signal intended to reduce unwanted external sound.
This can be particularly useful for:
- Air travel
- Train journeys
- Busy offices
- Commuting
- Listening around household noise
Three Noise-Control Modes
Bathys MG provides three environmental listening settings:
- Silent: Strongest noise attenuation for louder environments
- Soft: Lighter attenuation while retaining more environmental awareness
- Transparent: Allows outside sound through for conversations and awareness
Silent Mode
Silent provides the strongest noise reduction and is intended for situations such as aircraft cabins and other consistently noisy environments.
Soft Mode
Soft provides lighter attenuation for environments where you still want some awareness of what is happening around you.
It can work particularly well at home or in an office.
Transparent Mode
Transparent mode uses the microphone system to let outside sound through.
This makes it easier to hold a conversation or hear announcements without removing the headphones.
Eight Microphones
Bathys MG incorporates eight microphones across its noise-cancellation and communication systems.
Focal has revised the microphone implementation compared with the original Bathys to improve environmental control and voice isolation.
Clear Voice Capture
Dedicated microphones are used for calls so that your voice can be picked up separately from the broader active-noise-cancellation system.
Phone Calls
Calls can be handled through the headphones when using compatible Bluetooth equipment.
Bathys MG can also handle calls through USB where the connected device supports the standard USB audio protocol.
Microphone Does Not Operate in 3.5mm Jack Mode
The Bathys MG microphone system is not active when listening through the analogue 3.5mm input.
If call functionality is required, use Bluetooth or a compatible USB connection instead.
USB-DAC Mode
USB-DAC mode bypasses Bluetooth transmission and sends digital audio directly from a compatible source into the headphone's internal digital-to-analogue converter.
Bathys MG supports PCM playback up to:
24-bit / 192kHz.
Supported USB Resolutions
Focal specifies support for:
- 44.1kHz at 16-bit or 24-bit
- 48kHz at 16-bit or 24-bit
- 88.2kHz at 16-bit or 24-bit
- 96kHz at 16-bit or 24-bit
- 192kHz at 16-bit or 24-bit
176.4kHz USB Audio Is Not Supported
Bathys MG supports several common USB PCM sample rates up to 192kHz, but Focal does not support 176.4kHz playback.
Why Use USB-DAC Mode?
Bluetooth is designed primarily for wireless convenience.
USB-DAC mode provides a direct digital connection and is the mode to consider when you want to hear Bathys MG without relying on a Bluetooth codec.
USB-C Cable Included
Focal supplies a 1.2m USB-C cable for charging and compatible USB-DAC operation.
Your USB Device Must Support USB Audio
A USB-C socket alone does not guarantee that a phone, tablet or computer will operate correctly as a USB audio source.
The source must support the required USB audio and host functions. Some mobile devices may also require USB OTG to be enabled or an appropriate adaptor.
USB-DAC Mode Limitations
When Bathys MG is switched to USB-DAC mode, several wireless functions behave differently.
Focal specifies that:
- Voice prompts are unavailable
- The proximity sensor does not provide automatic pause and resume
- The Focal and Naim app cannot change settings while the headphones are connected in USB-DAC mode
- Settings previously stored through the app remain applied
iOS Calls Are Not Available in USB-DAC Mode
Focal specifies that phone-call functionality is unavailable on iOS while using USB-DAC mode.
Use Bluetooth if you need normal call handling from an iPhone.
3.5mm Analogue Connection
A 1.2m 3.5mm cable is also supplied for conventional analogue connection.
This allows Bathys MG to be used with:
- Portable music players
- Hi-Fi components with suitable headphone outputs
- In-flight entertainment systems with compatible connections
- DACs and headphone amplifiers
- Other equipment with a 3.5mm analogue headphone output
Bathys MG Still Requires Battery Power in Jack Mode
Bathys MG is an active headphone and the analogue signal still passes through its internal electronics.
If the battery is completely flat, the headphones will not play through the 3.5mm input.
Not a Passive Headphone
This is an important difference between Bathys MG and conventional wired Focal headphones such as Azurys, Hadenys or Clear MG.
Bathys MG relies on its built-in electronics regardless of whether you use Bluetooth, USB or the analogue jack connection.
30-Hour Bluetooth Battery Life
Focal specifies up to:
30 hours with Bluetooth and active noise cancellation.
Actual runtime will depend on factors such as playback level, wireless conditions and usage.
35 Hours in Jack Mode
Using the analogue wired input increases Focal's published battery life to:
35 hours.
42 Hours in USB-DAC Mode
Focal's technical specification gives up to:
42 hours in USB-DAC mode.
15-Minute Fast Charge
A short charge can be particularly useful before travelling.
Focal states that approximately:
15 minutes of charging provides around five additional hours of listening.
Approximately 1.5-Hour Full Charge
With a suitable power source, Focal specifies a charging time of around:
1.5 hours.
1060mAh Lithium-Ion Battery
The internal rechargeable battery has a published capacity of:
1060mAh.
Use a Suitable USB Power Source
Focal recommends a good-quality USB power source capable of supplying approximately 5V DC and 2A for effective charging.
Focal and Naim App
The Focal and Naim application provides access to headphone configuration from a compatible smartphone.
Functions include:
- Equaliser adjustment
- Mimi Hearing personalisation
- Battery information
- Lighting control
- Headphone settings
- Voice-assistant configuration
- Firmware updates
The App Connects Through Bluetooth
The Focal and Naim app requires the headphones to be connected in Bluetooth mode for configuration.
Settings saved to the headphones can continue to affect playback in other modes.
Five-Band Equaliser
The app includes a five-band graphical equaliser.
You can customise and save your own tonal settings, with Focal also providing preset options for different listening situations.
Mimi Hearing Personalisation
Mimi Hearing provides another form of personalisation.
A short hearing assessment is carried out through the Focal and Naim app, after which a profile can be stored in the headphones and applied to playback.
Once configured, the profile can remain active when using Bluetooth, the analogue jack or USB-DAC mode.
Voice Assistants
Bathys MG can be configured through the app for compatible voice assistants including:
- Google Assistant
- Amazon Alexa
- Siri
Backlit Focal Logos
The Focal logo on the earcups can be illuminated.
If you prefer something less conspicuous, the lighting can be dimmed or switched off through the app.
Closed-Back Construction
Bathys MG uses closed earcups rather than an acoustically open design.
This works naturally with the active noise-cancellation system and also helps reduce sound leakage to people nearby.
Suitable for Travel
The combination of closed-back construction, ANC, wireless playback, microphone system and carrying case makes Bathys MG particularly well suited to listening away from a dedicated Hi-Fi system.
Typical uses include:
- Air travel
- Rail travel
- Commuting
- Hotels
- Office listening
- Working from a laptop
350g Weight
Bathys MG weighs approximately:
350g.
This is more substantial than many lightweight consumer Bluetooth headphones, so trying the fit is worthwhile if you expect to wear them for very long sessions.
Genuine Leather Headband
Focal uses genuine leather across the headband as part of its premium construction.
The headband is shaped to distribute the headphone's weight across the top of the head.
Ergonomic Foam Earpads
The circumaural pads surround the ears and use ergonomic foam to provide cushioning and assist the acoustic seal required for effective low-frequency reproduction and noise cancellation.
Aluminium and Magnesium Construction
Focal uses lightweight metals including aluminium and magnesium through the yoke and supporting structures.
The aim is to combine rigidity with a manageable overall weight for a headphone containing batteries, amplification, DAC circuitry, microphones and wireless electronics.
Carrying Case Included
A protective carrying case is supplied.
The case measures approximately:
- Width: 21cm
- Height: 24cm
- Depth: 7cm
Two Cables Included
Focal supplies:
- 1.2m 3.5mm analogue jack cable
- 1.2m USB-C cable
No Separate Headphone Adaptor Is Listed
Focal does not list a 6.35mm headphone adaptor or airline adaptor among the supplied Bathys MG accessories.
If your source requires another connector type, a suitable adaptor may be required.
Available Finishes
Focal offers Bathys MG in:
Chestnut
The Chestnut finish uses a warm brown tone inspired by Focal's Clear MG headphones.
Graphen Grey
Graphen Grey provides the darker, more understated alternative with a mineral grey appearance.
Bathys MG or Standard Bathys?
Bathys
- 40mm aluminium/magnesium M-dome drivers
- Bluetooth 5.1
- Active noise cancellation
- USB-DAC mode
- aptX Adaptive
- Wireless and wired listening
Bathys MG
- 40mm pure-magnesium M-dome drivers
- Bluetooth 5.2
- Optimised microphone system
- Active noise cancellation
- USB-DAC mode
- aptX Adaptive
- Wireless and wired listening
The most significant difference is acoustic: Bathys MG moves to Focal's pure-magnesium M-dome driver technology. It also gains Bluetooth 5.2 and revised microphones for the noise-cancellation system.
Compare the Focal Bathys at Audio T.
Bathys MG or Azurys?
Azurys
- Passive wired headphones
- No battery required
- No Bluetooth
- No active noise cancellation
- 3.5mm analogue connection
- Aluminium/magnesium drivers
- 306g
Bathys MG
- Active wireless headphones
- Rechargeable battery
- Bluetooth 5.2
- Active noise cancellation
- USB-DAC mode
- Pure-magnesium drivers
- 350g
If you predominantly listen through a conventional Hi-Fi headphone output and do not need wireless features, Azurys is the simpler passive option. Bathys MG is much better suited to someone who wants high-quality portable listening with Bluetooth, ANC and USB-DAC functionality.
Compare the Focal Azurys at Audio T.
Who Are the Focal Bathys MG For?
Well Suited To
- Premium wireless listening
- Air travel
- Train journeys
- Commuting
- Office listening
- Bluetooth smartphones
- Bluetooth laptops
- aptX Adaptive devices
- USB-DAC computer listening
- 24-bit/192kHz USB playback
- Phone and video calls
- Listeners wanting personalised EQ
- Listeners wanting active noise cancellation
Check Before Buying
- 350g headphone weight
- Battery required in every listening mode
- 3.5mm jack mode is not passive
- Microphone unavailable in jack mode
- 176.4kHz USB playback is not supported
- iOS calls unavailable in USB-DAC mode
- App configuration requires Bluetooth mode
- USB source must support USB audio
- No 6.35mm adaptor listed as supplied
Key Features
- Focal Bathys MG
- Wireless closed-back headphones
- Active noise cancellation
- 40mm drivers
- Pure-magnesium diaphragm
- M-shaped dome
- Drivers made in France
- 10Hz–22kHz ±3dB
- Less than 0.2% harmonic distortion at 1kHz
- Bluetooth 5.2
- Bluetooth Multipoint
- 15m published Bluetooth range
- SBC codec
- AAC codec
- aptX codec
- aptX Adaptive codec
- Eight microphones
- Silent ANC mode
- Soft ANC mode
- Transparent mode
- USB-DAC mode
- Up to 24-bit/192kHz PCM
- 3.5mm analogue input
- 30-hour Bluetooth ANC battery
- 35-hour jack battery
- 42-hour USB-DAC battery
- 15-minute fast charge
- Five hours from quick charge
- 1.5-hour charging time
- 1060mAh lithium-ion battery
- Focal and Naim app
- Mimi Hearing personalisation
- Five-band EQ
- Voice-assistant support
- Backlit Focal logos
- Genuine leather headband
- Ergonomic foam earpads
- Aluminium and magnesium yoke
- 350g weight
- 1.2m jack cable supplied
- 1.2m USB-C cable supplied
- Protective carrying case
- Chestnut finish
- Graphen Grey finish
Frequently Asked Questions
What are the Focal Bathys MG?
Premium closed-back Bluetooth headphones with active noise cancellation, built-in amplification and USB-DAC functionality.
What does MG mean?
It refers to the pure-magnesium M-dome drivers used in Bathys MG.
How large are the drivers?
40mm.
Where are the drivers made?
Focal manufactures them in its workshops in France.
What is the frequency response?
10Hz to 22kHz ±3dB.
Do Bathys MG have active noise cancellation?
Yes.
Which ANC modes are provided?
Silent, Soft and Transparent.
What does Transparent mode do?
It allows more outside sound through the headphones so you can hear conversations and your surroundings without taking them off.
How many microphones are built in?
Eight.
Which Bluetooth version is used?
Bluetooth 5.2.
Do Bathys MG support Multipoint?
Yes. Two compatible devices can remain connected simultaneously, although only one audio stream plays at a time.
How many Bluetooth devices can be remembered?
Up to eight paired devices can be stored.
Which Bluetooth codecs are supported?
SBC, AAC, aptX and aptX Adaptive.
Do they support aptX HD?
Focal specifies aptX and aptX Adaptive rather than listing aptX HD separately for Bathys MG.
What is the Bluetooth range?
Focal specifies up to approximately 15 metres in suitable unobstructed conditions.
Do Bathys MG work over USB?
Yes. USB-DAC mode allows compatible digital audio to be sent directly to the headphone.
What is the maximum USB resolution?
Up to 24-bit/192kHz PCM.
Does it support 176.4kHz USB audio?
No.
Does it support 192kHz USB audio?
Yes, at 16-bit or 24-bit.
Can I use USB-DAC mode with a phone?
Yes, provided the phone supports the necessary USB audio and host functions. Some devices may require USB OTG settings or a suitable adaptor.
Can I take calls on an iPhone while using USB-DAC mode?
No. Focal specifies that calls are unavailable on iOS in USB-DAC mode.
Do they have a 3.5mm input?
Yes. A 1.2m analogue jack cable is supplied.
Can I listen through the 3.5mm cable with a flat battery?
No. Bathys MG requires battery power in all listening modes, including the analogue jack input.
Are Bathys MG passive when connected by cable?
No. The internal active electronics remain part of the signal path.
Does the microphone work through the 3.5mm cable?
No. Focal states that the microphones are not active in Jack mode.
How long does the battery last using Bluetooth?
Up to approximately 30 hours with Bluetooth and active noise cancellation.
How long does it last using the analogue cable?
Up to approximately 35 hours.
How long does it last in USB-DAC mode?
Focal's technical specification gives up to approximately 42 hours.
How long does a full charge take?
Approximately 1.5 hours with a suitable charger.
Does Bathys MG support fast charging?
Yes. Around 15 minutes of charging provides approximately five hours of additional listening.
What battery is fitted?
A rechargeable 1060mAh lithium-ion battery.
Is there an app?
Yes. Bathys MG works with the Focal and Naim application.
What can the app control?
Functions include EQ, Mimi Hearing personalisation, battery information, lighting, voice-assistant setup, headphone settings and firmware updates.
Can I connect the app while using USB-DAC mode?
No. App configuration requires a Bluetooth connection, although settings already stored in the headphones continue to apply.
What is Mimi Hearing?
It is a personalised hearing-profile system accessed through the Focal and Naim app. Once configured, the resulting profile can remain active across Bluetooth, jack and USB-DAC listening.
Does it have an equaliser?
Yes. The app provides a five-band graphical EQ.
Does it work with voice assistants?
Focal provides configuration for Google Assistant, Amazon Alexa and Siri through the app.
Can the Focal logos be switched off?
Yes. The logo lighting can be dimmed or disabled through the app.
How much do Bathys MG weigh?
Approximately 350g.
Is a carrying case included?
Yes.
What cables are included?
A 1.2m 3.5mm analogue cable and a 1.2m USB-C cable.
Is a 6.35mm adaptor included?
Focal does not list one among the supplied accessories.
What finishes are available?
Chestnut and Graphen Grey.
What is the difference between Bathys and Bathys MG?
Bathys MG uses pure-magnesium M-dome drivers instead of the aluminium/magnesium drivers used by Bathys. It also uses Bluetooth 5.2 and an optimised microphone system.
Are Bathys MG better suited to travel than passive Focal headphones?
They are certainly more convenient for many journeys because Bluetooth, active noise cancellation, microphones and USB-DAC functionality are all built in. Passive headphones remain attractive where simplicity and battery-free wired listening matter more.
Related Focal Products and Audio T Guides
Why Buy From Audio T?
- Focal headphone demonstrations
- Bathys and Bathys MG comparisons
- Wired and wireless headphone advice
- Headphone comfort and fit guidance
- Bluetooth setup
- USB-DAC setup
- Phone and tablet compatibility advice
- Focal and Naim app setup
- Noise-cancellation demonstrations
- DAC and headphone source advice
- Part-exchange options
- Setup and ongoing after-sales support
Contact your local Audio T store to arrange a Focal Bathys MG demonstration or discuss Bluetooth, USB-DAC, active noise cancellation and source compatibility.